1. Tacky adhesive, blue or white, behind the bottom of clocks, pictures, ect. keeps them on the wall. Under trays or items on tables or shelves keeps them in place when traveling.
2. 3/4 X 3/4" wood strips with the appropriate slots in them screwed under our table with a 9X13" cake pan slid in for small items, table stuff. In a pinch, make a cake!
3. 5mm high brightness LED and a 400 to 1k resistor (Radio Shack) , wire in series with each other and across the switch inputs on the bathroom light (in parallel with the switch). Drill a 3/16" hole in the solid part of the fixture and push led through. when the switch is off, LED will make a nightlight in the bathroom. If the .03 amp use bothers you in the day, wire in another switch in series. Higher resistor values make the LED dimmer and use less power.
4. Our fifth wheel has space above the kitchen cabinets with a decorative rail all around. DW got decorative baskets for up there, we store tablecloths, dishtowels, dried goods, ect. Anything light and heat resistant.
5. Since we rarely use our oven, it makes a great light proof bread box. With the pilot off of course.
6. Replaced the noisy bathroom fan with two 5" computer muffin fans, much quieter and .36 amp draw total.
7. Clear plexiglass strips approx 2" high by the right length to slip upright behind the stiles inside the medicine cabinet. Prevents small bottles from falling out yet you can still see everything.
8. Similar strips glued/screwed across the corner shelves in the shower keep bottles ect, in place. Make sure to leave a space at the bottom for drainage.
9. Winter camping we put the heat shrink type plastic over the screen door, helps keep the draft off the DW.
10. Took the absolutely horrible pull-out couch frame out and replaced it with lift out plywood support panels.
Added a good 12 cu. ft. of storage, exchanged 50# plus of unused torture equipment with things we actually need.
All right that's 10, somebody can surely do 11!