One of the best things I've ever done was make use of the space above the garage door. This picture is jut a piece of adjustable wire rack and some fixtures. Lag bolted the fixture to the ceiling. Drilled some bolt holes through the rack uprights, sawed the uprights JUST short enough to clear the garage door and then installed the racks and let gravity do it's thing. Honestly, I use these more than any other shelf/rack in the garage.
After that it has to be tire storage. (Autocross and Open track. Both kill tires, these are easy to get to, easy to load and store.)
Then it's helmet, creeper and ramp storage.
And finally, cause it's HOT down here. Ceiling fans.
(NOTE: The fans don't do as good of a job as I wish, especially in 90+. But they do great for circulation. In other words, don't rely on them as a single point cooling system, IMHO.)