Wash your roof! For rubber roofs, use proper soap. When you are done, have the roof conditioned.
Keep the window seals cleaned and conditioned.
Winterize water system with anti-freeze for RV water system. Turn off propane and drain the tanks.
Keep it washed and waxed. Keep unit covered if possible.
Water Heater, Refrigerator, Furnace keep the burners clean.
Keep checking the oil and Keep the air cleaner clean. Make sure all lights and air is off before starting.
When storing, take the weight off of them. And also release 10 psi from them. Also cover them with tire covers to protect them from sunshine.