In my experience, most light work can be done with the bike stored upside down (standing on the handlebars and seat).
Of course, I'm assuming that you're talking about a road bike.
Other bikes, like a mountainbike with a twist-shifters or trigger-shifting, might not be as well suited.
bicycles.stackexchange.com/users/7118/user2432675
Before I bought a bike stand, I used the bike rack on my car.
I still use it in a pinch.
bicycles.stackexchange.com/users/346/Brian Genisio
I have two large hooks attached to my basement ceiling.
I attach a 1 inch cargo strap (look for them in camping supplies) from the hook to my saddle and a second around the bars and stem.
This suspends the bike while allowing the wheels and crank to spin freely.
By adjusting the strap length I can position the bike so the area being worked on is close to eye level.
The hooks were less than $3 and the straps were $3 each.
bicycles.stackexchange.com/users/3083/mikes
I have double kickstand on the bike which can act as mini repair stand.
I pull the bike on the kickstand, and put some weight (u-lock and chain) on the front of the bike so it tilts forward and back wheel gets lifted in the air.
bicycles.stackexchange.com/users/5563/Davorin Ruševljan
Here is a cheap ($20) bike stand that elevates the rear wheel:
http://www.amazon.com/Sunlite-Bracket-Bicycle-Display-Stand/dp/B000C17HJ4 Note that it works best with thinner-tubed steel bikes, and doesn't necessarily hold up a bike with a thick aluminum downtube optimally.
bicycles.stackexchange.com/users/5702/Alan Gerber
Turn the bike upside down and clamp the handle bar stem in the jaws of a WorkMate workbench and rest the seat on the opposite end of the WorkMate work surface.
Turning the seat around backwards on its stem may be helpful.
bicycles.stackexchange.com/users/14621/Lincoln Webster
I use two high chairs (with straight backrest) With one or two broomsticks inbetween them to hold the bike up.
bicycles.stackexchange.com/users/52666/user52666
My solution for this is a kickstand.
It keeps the bicycle upright with both wheels on the ground.
If you need to adjust the gears, you can slightly tilt the bicycle to stand only on the kickstand and not on the rear wheel.
Then the rear wheel is free to rotate, but it requires continuously keeping the bicycle in the slightly tilted position.
It's a one-handed job though, so the other hand is free to rotate the cranks.
Don't put too high stress on the kickstand though or else you may be looking for a new frame, as you accidentally bent the chainstays of the old frame!
bicycles.stackexchange.com/users/33932/juhist
A cheap solution is a wall-mounted bike holding stand.
The simple ones are just a couple of prongs that stick out from the wall and support the top tube of your bike.
Something like this is $US40 or you can get fancy with this (will work better with sloping top tubes)
I suspect you could build one out of a 1.5m length of timber and some screws quite easily, although attaching it to the wall would require a little care.
The rope-based hanging bike storage systems also work well for this if you can put up with the bike swinging round.
Those allow better access, but the bike moves.
A solid wall mount won't move but you have to take the bike down and flip it round to access the other side, and you can't turn the handlebars much.
bicycles.stackexchange.com/users/7044/Móż
I want to tweak my gears, from time to time: Adjust my front and rear derailleur limits, see if the shifts are smooth, make small adjustments on the cable tension, and so on.   Is there any way to get the bike in position without help of anyone?  I don't want to spend money on a bike stand.
How to position a bike for work without a stand
bicycles.stackexchange.com
<gears>
bicycles.stackexchange.com/questions/16103
bicycles.stackexchange.com/users/6999/danieltorres
Most light work can be done with the bike stored upside down (standing on the handlebars and seat). However, the kickstand can also be used to hold the bike while you work. Other options include large hooks in the ceiling and a wall-mounted bike holding stand. You can use a double kickstand or turn the bike upside down, resting it on the handlebars. The bike can be suspended from hooks on the ceiling or rested on a solid wall mount, turning it around to work on the other side.
You can use a double kickstand or turn the bike upside down, resting it on the handlebars. The bike can be suspended from hooks on the ceiling You can also use a solid wall mount, turning it around to work on the other side.