I have one list of things to secure before driving. If I miss one, it could be messy, but not expensive. For the expensive "oops", I bought a pack of cheap spring loaded cloths pins. Used a label maker to print labels for "Water Hose", "Electric", "HWH Jacks", "Sewer Hose", etc. Anything that gets expensive quick if I forget before I pull out. When I hook up at a CG, I put the appropriate cloths pin on the turned down sun visor. As I'm preparing to leave, I remove the cloths pins as I take care of the item and put them in one of the compartments in the "doghouse".
As I age, all It takes is for somebody to interrupt my routine by waving at me. :)