I currently use the "clothespin method"—I have a small pile of clothespins with checklist items marked via sharpie. They start clipped to the sun visor in the cab, and are removed and dropped in the doghouse storage bin as they are dealt with.
The current pile, in random order:
Sewer (disconnect and/or dump)
Water Fill
Water Hose
Compartments (outside compartment doors latched)
Water Pump (turned off—personal preference for travel)
Welcome Mat
TV Antenna
Oil (check level in engine)
Trash
Bedroom Blinds (rear window ones opened, sides secured)
Electric
Awning
Bedroom windows (side jalousie windows need to be closed for driving)
Tire PSI
Count Noses
Prayer
I'd have one for the entry step, but it has its own light on the dash on my RV that I figure ought to be a sufficient reminder. There is also the general "stow stuff so it doesn't go flying" that needs to be done.