Garage bike rack are useful to save some space. Especially if you had quite a narrow garage. Probably the bike could be park there but it kind of narrowed your space to open the car door or blocking your way. So, its better to be mounted on the wall. The higher are far more better untill it reach head clearence, then it won’t bump into your or anybody heads. But that would be it if you put the bike horisontally. There are also another idea for the rack that will be hung the bike vertically. This one couldn’t be to high. But it would be usefull if you had a lot of bikes.
Above the vertical bike rack could be put an open shelve. The shelve are probably best for storing your helmet or other bike stuffs. One thing that you should consider by using the bike rack are it has to be easy to store and easily to take. Unless you had those principle then everytime you want to use the bike will take sometimes. You don’t want that. in my opinion that is the ideal garage bike rack. Wheter its vertical or horisontal, it depend on your garage size and situation. Ask somebody’s profesional to do the workmanship for the rack.
Garage bike rack is a perfect garage space solution. I’m not suggesting that you should made the rack before you had the bike. But on the contrary, because there a lot of bike types and each one of it could have difference rack to build. There are probably some general racks that you can bought on bike shops. Or to make it easy you could buy the bike and the rack altogether. And when you get into the garage you could installed it by yourself. But making the racks it self are probably harder.