To make working on stuff better, lets see what you have come up with.

I have copied suggestions from other forums and added to the collection.

1. Rubber mats for horse stalls - make great pads to keep your feet from hurting and hard material your creeper seat can roll across and they dont slide out from under you.
2. Laptop and flat screen tv - for a cheap garage computer for tracing wiring diagrams.
3. old cheap roll around tool box - make great welder carts and storage for welding/fabrication tools.
4. installed a poly parking lot bumper keep my front end off the back of the garage.
5. Colored electrical tape at the ends of tools for quick Identification.
6. Home Depot Rustoleum Epoxy Garage Floor Kit: BEFORE MOVING IN. $200 and 3 weekends of labor (2 for prep, 1 for application and drying) -Not perfect but looks really great and makes cleanup easy. USE the anti-slip powder!
7. Retractable electric cord reel on the ceiling: I mounted mine right in the dead center of the garage and it's the most awesome time saver / annoyance saver ever.
8. Retractable air hose reel on the ceiling: My next purchase. I am putting my air compressor into a Gladiator Garageworks cabinet, then applying dynomat and the foil insulation to the bottom section of the cabinet where my air compressor is (cuts down on noise), then adding a retractable reel air hose close to the electric cord reel.
8. Sink
9. Good lighting: I upgraded to LED lighting, but I'm adding 2 more LED lights and a dedicated over-bench light.
10. Carpet scraps for laying on
11. Bench Grinder with a dewalt wire wheel.
12. Bench Vice
13. Rechargeable blutooth speaker lets me run a show or music off of the phone and still get phone calls.
14. T-handle ratcheting alan wrench.
15. I gut my old 18 volt batteries and screw the shells on the wall, then I use them to house my cordless drills
16. Simple, but I keep a paper towel and toilet paper dispenser on the wall, can buy one at HF.
17. I made a sheet metal holder for the HF nitrile gloves mounted to the wall to serve as a dispenser, can buy one at HF.
18. have two wooden boxes under the workbench, one for clean and one for dirty shop towels. (I wash and reuse mine)
19. made four 10 1/2 by 10 1/2 by 7 blocks out of two by fours. three on top, three on the bottom and two runners. They make great supports for any thing, vehicles, for cutting wood, a quick step, etc.
20. old bathroom rugs, they're the best for lying on, the toilet ones are great for motorcycles, the cutout fits around the tires.
21. 4 inch PVC cut it to the lengths I need and mount them to the wall. They make great place to put moldings, wood trim and a variety of other things.
22. shelves above garage door rails for storage before.
23. a work bench with shelves under it for storage.
24. Old cabinets for storing paint,brake clean etc
25. Set up a commercial account for yourself at your local parts stores, they often sell brake clean for $2.00 a can to "commercial" clients along with other discounts on parts behind the counter. You dont need a charge account or a tax number.
26. Keep your eyes/ears open for someone that updates hardware stores, I got a rack of bolt bins from an old hardware store for $15
27. Check the insulation in the attic above your garage if its not already climate controlled, it helps alot .
28. Tire storage hangs from ceiling to keep them out of the way.
29. Peg-board double loop screwdriver holders (that never seem to work for screwdrivers I own), mounted to the side of the toolbox to hold the 1/2" drive extra long ratchets and extension
30. Peg-board fork things, again on the side of the toolbox to hold the vice-grips.
31. Plastic pipe with caps to hold the drippy grease guns