I use these
RVMinders.
I added "Propane On" and "E-Brake On" on the blank ones (my e-brake light doesn't work). And on one I don't need (no slide, no toad, no tv/antenna), I changed it to "Fridge on 12v".
I find them very easy to use. Simply do my walk around, and then when I climb in the driver's seat, take off the strips one by one.
For the interior stuff, my rule is that everything must have a proper place and it stays there when not in use. So I just put everything away before driving, which is easy as I put most stuff away as I finish using it.
When I had my trailer, I used the excel spreadsheet, but I wanted something simpler for the clipper since it is really a "hop in and drive" type RV.