Bikes take up a lot of space in the garage, and they try to get tangled up with each other, which is potentially damaging to spokes. In the past I used a hook on a cord (you can see green cord in the picture) but catching the hook in the wheel was a bit like bobbing for apples. Frustrating.
So I turned to wooden hooks. One bit of 2 by one one screw to fix it movably to a roof beam, one hole, drilled at a slight angle, one bit of dowel whacked in the hole, and - Robert est votre oncle, as our French cousins would say.
I'm not claiming this as an original invention, just a bloody good solution to bike storage that deserves to be more widely practiced.
I also recommend the Phoenix bike holder, which is my invention and is here: http://www.greenhealth.org.uk/Phoenix%20Bike%20Stand.htm