You've got to be more creative with a small space. The first decision I made with my 20x21 two-car was that I was only going to have one car in it. If a garage becomes just a box to store stuff (whether it's cars, kids' toys, lawn equipment, or whatever), you lose the room's real utility -- which is a place to get stuff done.
My little garage has ten work surfaces in it, which is kind of ridiculous -- but which also illustrates how much you can fit in a small garage if you take the time to organize your stuff, and make some hard decisions about what to keep and what to get rid of -- and what to store in that shed you're going to build.
Let me apologize in advance for there being no blue oval and so many pictures. But I'm proud of the place -- I did all the work myself, including setting the tile and digging the pit for the lift. The total budget, including the floor, cabinets, benches and lift was less than $3,500. Everything in the place is second-hand, re-purposed or home-made.
I also made a website for it:
http://www.12-gaugegarage.com
Work benches that fold down from the wall:
Is it always this clean? No. Not by a long shot.
But it does go back to clean very quickly -- that's the real accomplishment of it, I think. I finally took the time to work out a place for everything to go when It's not being used.
In practice, it makes a huge difference not having to spend so much time looking for things you've misplaced. I spent years doing that.