If anyone else has some good ideas, please keep the post going. Pics really help.
An old plastic bottle on the work bench is good for disposing of old nails, screws, blades, or anything sharp that could get into a tire. When it's full, just screw on the lid and dump it in the trash.
I keep a box of old food containers to use for sorting parts, cleaning brushes, soaking bearings, etc. I even use them under the leg of my EZ Up to move it around in camp.
A simple peg board cabinet door with long hooks keeps all my rolls of stuff organized and handy.
A piece of plywood with a hole in the middle makes a convenient work surface next to the work bench while still leaving room for disposing of trash.
The cheap furniture dollies ($10 at Harbor Freight) make for convenient storage under your trailer. I keep camping supplies in Rubbermaid tubs and even spare tires under my camper when not in use.
A cheap mouse pad from the dollar store allows you to slide your coffee maker around easily without scratching. I use one in my kitchen also.