When It Hits the Fan/Generalities

Step One: prepare for something small..
Survivability depends on what you know, how fit you are and available tools and resources. Fitness is the most important factor, if you are fit you can cope with mistakes and exert more effort to gather resources. The next important trait is having useful knowledge, this prevents making mistakes, reduces wasted energy and helps to keep moral up. It also serve to increase the chances of surviving without tools or resources. If you know how to improvise your own tools and locate water and food you have not only gained time but increased your value to others and you will have an advantage over any competition (including wildlife).
By having tools and resources you will be less dependent on others, reduce your movements/efforts and have something to bargain with if need arises, even for your life. Depending on the situation this can makes you also a bigger and slow target, especially if because of them you became static, for example not leaving your house amidst a flood or an epidemy because of excessive reliance/dependency on what you have stored. Balance is of the essence. 
Knowledge.
Be aware and informed. What could be an usual emergency? Some emergencies are indeed expected to occur. It might be a flood, a hurricane, a tornado, or an earthquake. All this things have a distinct and knowable risk factor, even if unpredictable, some events are dependent on specific geographic location. Do you live near a river bed ? A atomic power plant ?
Knowing your surroundings and local risk factors will always help you be prepared and safer and should be also a factor for you daily decisions. Be aware of emergency plans for the area where you live, work or visit and learn the general actions that increase survivability in the expected regional emergencies (higher probability), like how to act in an earthquake or a tsunami if that is the case.
There are many information and know how that is very low in complexity and can prove indispensable in a large array of situations. You can easily get some camping experience, practice and learn how to tie different utilitarian use knots, to create fire (especially using only wood) even learn how to meditate (or hypnosis). Knowing your blood type, allergies, the basics of first aid, learn how to swim and fish, how to can food and safely use it, to handle firearms and bows, repair a car and drive it, ride a horse or bicycle, all this type of knowledge will help you be more self-reliant and independent and so increase your chances in a myriad of unforeseen situations.
Experience.
There is no better thing that first person experience, this is the best way to not only learn but understand your limits and find new ways to solve unexpected problems. It will help everyone survive dangerous situations (such as storms or earthquakes), or in dangerous places (such as the desert, the mountains, and the jungle). Useful skills like lighting a fire, finding shelter, making water safe to drink, finding and identifying food, treating injuries, and climbing, swimming, and using specific or makeshift tools.
The more experience one has the more self confidence and keeping the moral up it is. In order to overcome the effects difficulty it is important to study and understand how stress may affect your action in both good and bad ways.
Backpacking.
Having an understanding about your priorities, the needed supplies to address your requirements is extremely useful. Management of resources and deciding how and what to carry is a science in itself. There is a large quantity of books that deals exclusively with this subject directed to specific target audiences, in special to the habitual traveler but also for the wildlife experience. How and what to pack is a learning process that improves with experience.
Backpackers use lightweight equipment that can be carried long distances on foot, this may include a tent or shelter. Enabling a person to hike across the land, camping at remote spots. Backpacking equipment typically costs more that other type of equipment because of the materials used (resistance and weight) and the necessity of self reliability (like including their own power-supply).
Camping.
Camping and other outdoor recreational activities are great to build self reliance and confidence. It can even provide the experience of being away from civilization. Camping may involve the use of a tent, a primitive structure, or no shelter at all.
Canoe camping is similar to backpacking, but uses canoes for transportation; much more weight and bulk can be carried in a canoe or kayak than in a backpack. Canoe camping is common in North America.
Anther form is the bicycle touring that combines camping with cycling. Where a bicycle is used to carry the gear and as the primary means of transportation, allowing greater distances to be covered than backpacking although less capacity for storage.
Motorcycle camping is more comparable to bicycle camping than car camping, due to the limited storage capacity of the motorbike. Motorcycle camping riders, as well as bicycle touring riders, often use some of the same equipment as backpackers, due to the lighter weights and compact dimensions associated with backpacking equipment.
"Winter Camping" refers to the experience of camping outside when there is sufficient snow on the ground. Some campers enjoy the challenge this form of recreation brings.
Wild Camping too, is a growing choice by people seeking the challenge of camping in the wilderness, without campsite amenities. It is a great way of enjoying the solitude and beauty of the wilderness in its most pure form. It falls into the survivalist experience.
Survivalists.
Survivalist can be defined as experience campers that have learned the skills needed to survive out-of-doors in a situation of scarcity. It require skills in obtaining food from the wild, emergency medical treatments, orienteering, and pioneering. Skills used on a more permanent basis, or as a component of daily life are referred to as bushcraft.
Campers and outdoors people have adapted their forms of camping and survival to suit extremely cold nights and limited mobility or evacuation. Methods of survival when winter camping include building snow shelters (quinzhees), dressing in "layers," staying dry, using low-temperature sleeping bags, and fueling the body with appropriate food.
Practicers of this type of wilderness challenge face a different range of dangers. An environment may be dry, wet, hot, cold, high altitude, low altitude, desert, rural, urban, wilderness, subterranean, or an island. There are four basic necessities of life which apply in all of these cases: shelter, water, fire, and food. A fifth is oxygen for high altitudes and subterranean environments, and also specific survival situations such as drowning and landslide/avalanche.
Developments in outdoor equipment and pruning of survival techniques have skewed the scale towards man- if one is prepared, but there is nothing to replace experience in a survival situation.
Bushcraft.
Bushcraft is a long-term extension of survival skills. A popular term for wilderness skills in Australia, New Zealand and South Africa, the term was popularized in the northern hemisphere by Mors Kochanski and recently gained considerable currency in the United Kingdom due to the popularity of Ray Mears and his bushcraft and survival television programs.
Bushcraft is about surviving and thriving in the natural environment, and the acquisition of skills and knowledge to do so. Bushcraft includes all of the survivalist's skills but also includes more complex knowledge; firecraft, tracking, hunting, shelter building, the use of tools such as knives and axes, foraging, hand-carving wood, container construction from natural materials, rope and twine-making, and many others.
Things you should carry with you at any time.
Strive to at all times carry simple items that in a SHTF situation may make you life easier.
I keep small tins and in them individually I have mini-kits that stow easily anywhere and everywhere - in a purse, backpack, under the seat in the car. In them I carry the following items - a magnesium fire starter block with a metal scraper attached - can be got at hardware store, outdoor shop - its about 3 inches by 1/4" wide with a flint down one side, the metal scraper lets you shave off pieces and then you can strike the flint with it or against a piece of granite to generate a spark - starts a fire even with wet material, use with care as magnesium flares hot and fast. Super inexpensive they can be got on sale for about $3 or regular price about $8. In another small tin I have several fish hooks of various sizes, fishing line wrapped around a short piece of dowel or anything that lets you wrap about 20 ft of line -even a piece of stiff card will do. I include small split sinkers, a couple of little jig heads and small (1 to 1 1/2 inch) colored plastic baits, several shiny spinner pieces - just the metal - they sit flat in the tin. In another tin I have water purification tablets and a bottle of nascent iodine. I also have a tin with small multi-tools in them - there's a great one out for about $5-$10 that is flat about 2X3 inches and 1/16th thick of stainless steel that has 8 different functions. Have a look around at your local hardware store, sporting good stores. I've always got room for my kits - total investment is very small for extremely useful and potentially life saving items that can be kept in multiple locations so that you're more likely to have them close to hand than all packed in a nice bag in the closet at home. 
I've also picked up about 5 or 6 woven bracelets from the dollar store. The bracelet looks nice enough in neutral colors and is made of parachute cord. It pulls apart to provide 8 to 12 ft of tough cord. They fasten with a plastic lock snap and I keep one on the gear shift, one on my backpack strap, you get the idea. And I've got FirstAid tins - few bandaids, butterfly closures, alcohol swabs, safety pins, emergency blanket (those thin foil sheets that fold up to the size of a dollar), on old mirror from a compact, a whistle and a small plastic compass about the size of a quarter. I keep an eye out for tobacco tins, playing card tins, etc. you can decide what size tins you want to use - anything from a cigarette tin to larger ones and they are easy to find at garage sales, flea markets, dollar stores, 2nd hand stores, even your neighbor might have some they are throwing away - just start looking and you'll be surprised where you'll see them. With my tin kits in multiples, stashed on my person, and in different convenient places like the car and a backpack, my favorite slouch purse, I'm more likely to have emergency basics at hand than have a big go bag packed in my closet that's no good to me cause I likely won't be sitting home when It Hits The Fan. My little tin kits cover all the main emergency basics and don't take up a lot of room. Low cost, low hassle, takes up little room, and its been fun putting them together and playing my what if games cost, low hassle, take up small bit of space whether in a backpack bundled together - in the pockets of my favorite slouch purse. 
I also play a little game to keep myself alert and thinking and can be played anywhere - out for a walk in the park, on a hike in the forest, driving down the highway (don't get too distracted) of looking around my immediate environment and seeing what is there to scrounge/salvaged/items that can be used for purposes they're not made for, what the lay of the land is if I had to abandon my car, or what would be a good place to shelter for the night. I find it keeps my frame of mind positive as well, and you can carry a positive, can do attitude around with you everywhere you go. Hope someone finds this helpful - I'm not waiting for an apocalypse, but a severe weather event like SuperStormSandy or Katrina could be coming my way anytime. Since I began making up my tin kits, I find my confidence level has increased, I've learned a lot of new things, and it reduces fear. One last thing - get out and get comfy trying out your little kits, see what works, what can be improved, what challenges there are to using them instead of waiting til It Hits the Fan. Don't wait for a hazard to unfold to get a feel for your kits and tools. 
One type of object that should normally be carried is small or dividable item of tradable value. For instance a bracelet or necklace of gold or silver can be easily hidden and designed so links can be loosen to permit smaller trades in case of need or be used as bait for fishing. Depending on the situation most other items you carry can be used for trade, like a watch or even your shoes.
A good resistant belt, preferably longer than required. The belt buckler can also be a good tool beyond its primary function. Note that a belt can be a rapid way to create a tourniquet, to increase your reach or even to use as support in a zip line.
A time keeper, pressure resistant, non digital wrist-watch (or even better a chain-watch), that does not depend on batteries will be extremely helpfully and as seen above be an easily tradable item, it can also serve as a compass with the help of the sun, and will permit you to keep to a time table so to improve survivability.
For instance in a forest you may not be able to see the sun and in a survival situation you should keep night movement to a minimum, depending on the available light (moon, possibility to make and the duration of a torch) and expertize in night navigation. Even in a desert environment where nights will be cooler, and movement easy, it may not be advisable. A time keeper may also help avoid the hours of the day that temperatures are higher.
A small and reliable knife, is extremely useful in any situation even for day-to-day life, for instance in your key-chain. Not only useful as cutting tool or a possible weapon, the metal of the knife may also serve to create fire and serve as a crude mirror for signaling.
Things to plan at home.
Your home should be your base in an emergency. Ownership of the property should be a priority so you have full legal control over it and in dire circumstances no one will be able to claim if from you.
Select a property that is not in a flood basin or too near a river (or any water course), if it is, check historic records for the area and see if you can build it (or if it already is) well above the flood line. Having at least one inflatable boat will also be optimal. Note that this type of location it will prevent you to rely on a well for fresh water since there is a high degree of contaminants that can already be present of the natural water system or will be carried by any flood, as also make any food planting very susceptible to damage. Near the coast line you will have aggravated problems due to humidity and the presence of salt.
In a location with a high probability of heavy snow, at least one of the doors should open inward and preferably be in the 2-split format, this will prevent you becoming snowed in. Same is valid in areas prone to dense sandstorms. 
Assume 2-3 days without power and plan for that. This implies having three days of food that does not need cooking or refrigeration. Keep extra water put aside, flashlights, radio.
Step Two: supplies add more.
Planing for supplies is extremely important and constitutes an economical investment. Any item should be considered on the basis of its longevity, hardiness and usefulness.
Human survival priorities are found in the "Rule of Three":
There are also optimal times and locations to get your provisions for that special emergency or specialized material, consider that prices fluctuate with seasons for instance in the end of summer and winter season you can get good prices in sporting goods for the season that is ending.
Step Three: protection.
Now you have something worth defend, something that others less prepared my be willing to fight you for. Huddling in the your "cave" fearing the unknown is an unsettling feeling. How does one combat this? Depending on your frame of mind, this is either the most frightening or most exciting part of preparedness steps, you will, in most events be dealing with the most dangerous animal on Earth, man.
In most locations and if not when involved in a catastrophic situations one may rely in the Police (or other state forces) since the event will not be disruptive enough to make it impractical or place your personal security at a low priority, making you dire situation not particularly relevant in the general context of things.
Protection is a defensive stance, the tool-set may serve other purposes but consider this factor when you plan, since it is linked to what you have a need to protect. 
It is always best to be self reliant, by having a self sufficient strategy for active protection of your self, yours and your resources should be part of your survival strategy, this will help you fight off any intruder or scavenger be it human or beast.
Next... Reality Check.
The most important factors for survival are shelter, water and food, by order of importance. In most situations if you are exposed you will be in danger from the involvement, be it hostile or not at the time you see yourself in dire straits. The sooner you find a safe place and establish the minimum to shelter you from the environment the better changes you will have.
The next priority is locating a water source, without water you will quickly become dehydrated and unable to function, water has also the property to reduce the sensation of hunger (especially if you can warm it).
The last step to become self sufficient is food. These are the three things that will have primal importance in any situation, being deprived of anyone of them will assuredly put your life in danger.
When It Hits the Fan/Teaming
Going solo versus joining with family, a small team or a wider group.
When It Hits the Fan/Morals and law