I've built overhead storage all around my garage, everywhere I could. Mine's done with perforated angle and 3/4" plywood, because I had it. But I've also done it by making a frame with 2x2's, 24" deep x 8ft. long or whatever needed, with 1/2" plywood on top of that. The frame can be lagged right into the wall studs then suspended from the ceiling. I usually go about 24" from the ceiling.

Sure makes life a lot easier to store your crap up high out of the way! But it also makes it easier to gather even more crap. You wouldn't believe some of the stuff I've got on the shelves up high around my garage, there's most of a Willys Jeep up there and a whole lot of a Harley dresser. Plus tons of other shit.