I built a shop tool "lazy susan" on top of a rolling tool cart. Found a heavy-duty rotating platform at the local Home Depot, cut some MDF, screwed it all together and mounted the tools to it.
Hole in the center is for dust collection using a plastic gutter elbow feeding into a shop vac with the cords routed through the hole. Where the cords pass through the ducting, they are sealed with duct tape.
Works well for my little 2-car garage (which has room for only 1 car because I have too much junk in there).
I built overhead shelving to store parts and holiday decorations and a large bench along the wall where the car parks to hold totes for in progress projects and things I need access to more often (like home repair stuff). The bench holds the small parts washer I use for cleaning greasy parts and my miter saw (haven't figured out a better place for it yet).
I lined the floor between the benches and where the car parks with interlocking foam sheets to reduce fatigue and when I use the engine crane, I can pull them up and set them out of the way.
I have a couple of folding office tables that I can use for extra surface area when working on an involved project (like rebuilding the turbo in my 944 turbo). When they're not needed they fold up and can be stored overhead.
Since the walls were already finished I added wiring for lights and outlets on top of the wall using THHN and conduit. I've not had any issues with circuit overloading even with a fridge running on the circuit. I also don't run any large tools like welders or air compressors.
Lights are mounted under the shelving over the bench area and controlled with their own switch.
I do have a retractable flourescent drop light and a retractable extension cord mounted to the ceiling above the car.
Upcycled an old 22" LCD monitor by mounting it to the wall and building a Home Theater PC for the garage from old PC parts gathered over the years, now I can work in the shop and catch up on IMSA, PWC, Bathurst or SCCA racing or just watch some random documentaries on Youtube/Hulu/PBS, etc.
I should be getting an upright compressor from my Dad pretty soon so I've mounted a retractable hose reel to the wall in preparation. My little airbrush compressor can't really do much more than blow some air or fill up some tires. Being able to run an air ratchet would be kinda nice, but then I enjoy not making a ton of noise while in the garage so I can work really early or really late without pissing off the neighbors or especially the wife.