Here is my magic blister treatment method.
You need to have this stuff in your kit: Lanolin :
Yes, otherwise known as sheep grease.
Sold in pharmacies as an aid for breastfeeding mothers.
It is essentially a lubricant wax that will keep a blister happy and not stuck to what you put over it.
You put a daub of this directly on the blistered area.
Polysporin or that type of thing does not last as well as this stuff.
Lambs wool :
Take a bit of this and cover over the lanolin.
Regular cotton balls do not cut it.
Athletic Tape
: Use large strips of tape to cover over the blistered area and enough on each side to keep the tape attached.
Make quite a few layers.
You'll know it's enough when you put your boot back on and walking no longer hurts.
You can do this and leave it on until the end of your trip.
Ideally, you don't want to get the setup wet for the first day.
If it's pouring out, cover the whole mess with one layer of duct tape.
I'm honestly not sure why it works, but I have fixed some horribly nasty blisters with this method and walked for 100s of kilometers afterwards.
One particular happened on the Pacific Crest Trail, walking across a desert section, I wore a large circular area off my heel.
When I eventually limped to a halt in the first bit of shade I found, this stuff together got me moving again with zero pain.
Without fiddling with it, I was able to walk for days afterwards, 30+km per day.
outdoors.stackexchange.com/users/19/Ryley
Getting a pair of boots that correctly fit is very important.
Go to a reputable hiking shop and having a knowledgeable assistant give you multiple types of boots with different fits and see which feels best.
Changing inner sole thickness can be a big help to get the correct fit.
Properly breaking in your boots can be a huge help.
Wear them for an hour round the house, then a couple of hours the next day, then 20min short walk and gradually extend the length of the walk.
It helps your feet get used to the boots, and mould the boots to the shape of your foot.
Blister patches are a good treatment when you already have blisters - some people don't get on with them
but it's worth giving them a go.
Edit.
I forgot to mention socks.
Get proper walking socks, have a play with different thicknesses.
Sometimes wearing liner socks (really thin socks that you wear under your normal socks) can prevent blisters.
outdoors.stackexchange.com/users/83/Chris
I've always used Compeed blister plasters to treat a blister.
It's like covering the blister with a second, more durable skin.
You are supposed to leave the plaster on until it falls off naturally which, for me, is usually three or four days.
They are a little expensive but your feet will thank you for them.
By the way, I am not affiliated with Compeed in any way.
outdoors.stackexchange.com/users/1808/Richard Holyoak
The other answers are good, but here's my personal experience, as well as some of the common advice I didn't see.
Cause -
The two causes of blisters while hiking are moisture and friction.
This means you want to keep your feet dry and not sliding around, which is where proper boots comes in, as mentioned above.
Proactive
- You should treat blisters early.
As you are hiking you may notice a "hot spot" forming, which as it sounds, is simply a spot on your foot that feels slightly warm or hot.
They don't hurt, and you will be tempted to just ignore it.
But a hot spot will always form a blister, usually quickly.
In addition, the cause is often something simple to fix, like some bunched up sock or a bit of sand.
The moment you feel a hot spot forming stop and take off your boot, look at the spot and try to figure out what is the cause.
Wipe your foot off, with alcohol if possible. Put your boot back on and try to pull your socks so they are smooth and not bunched up.
If the hot spot is still there after this, you can try protecting it with some moleskin or some of the other suggestions to prevent it from becoming a full blister.
Reactive -
At the end of the day, after blisters have formed, I have found that rubbing alcohol works pretty well.
It dries them out and makes the skin harder for the next day.
I usually carry a small bottle of 91% (which is also an antiseptic and fire starter).
Alcohol displaces water and then dries very fast.
If your feet are sweating a lot during a hike you can even try wiping them down with alcohol mid-hike.
Popping -
The general rule of thumb is you should not pop blisters.
However, if you have to hike more, I have found the blister will almost always pop on its own anyway.
In that case, it's better to pop it in a clean environment rather than inside your dirty sweaty boot.
Take a needle, and heat it in a flame to sterilize.
Make a few holes near the base, just enough to let the fluid drain.
Clean the area with alcohol before and after.
outdoors.stackexchange.com/users/1778/DaleSwanson
You mention that they're newer boots in your post.
You could also wear them enough to make sure you've broken them in BEFORE your big hiking trip.
Wear them to work (if you can get away with it).
Wear them on the stairmaster in the gym
(if you're doing 20 minute sessions, blistering may not be as bad, and you can make sure to duct-tape / moleskip up your feet anywhere you might get a blister).
outdoors.stackexchange.com/users/651/DavidR
The most successful method for me is using a lot of shea butter.
Before and after a physical activity.
Before it reduces friction and acts as moisturizing.
After it can be used as a treatment cream because it hydrates your skin.
outdoors.stackexchange.com/users/12091/Adrian Ber
When hiking with a new pair of boots or if I haven't been hiking in a while, my feet might get blisters.    How can I treat a blister and keep hiking?   Are there things I can do to  prevent getting blisters?
How do I treat a blister? How can I prevent getting them in the first place?
outdoors.stackexchange.com
<hiking><boots><prevention><blisters>
outdoors.stackexchange.com/questions/157
outdoors.stackexchange.com/users/5/studiohack
The general rule of thumb is you should not pop blisters.  They should be treated early, and shea butter, blister patches and Compeed are recommended to treat blisters. Proper walking socks of suitable thickness as well as correctly fitting boots are very important. Treating blisters early, not popping them, using blister patches and shea butter are helpful, as are walking socks and boots that fit well.
You should treat blisters early without popping them. Blister patches and shea butter can help. Boots that fit well and proper walking socks help.