So having been a renter several times and now being an owner I feel the best advice I can offer everyone is tagging and labeling. The walk though is a great start but it has real limitations. It checks the boxes but the renter (especially a first timer) is going to forget a lot of it. Sure you give them your number but some people don't want to bother you or you miss that all important call. As an owner I genuinely want people to know how to work everything so that they are not only pleased but reduce the chances of braking anything.
So I found the answer to all of this is labeling and tags. I broke out my old trustworthy labeler and labeled everything could think of. The black and gray waste valves and evey other control on the RV but also the less thought of things like the storage cabinets. I labeled one for kitchen wares, pillows, sheets, wardrobe etc. Knowing my own RV quite well I know all the places where things fit just right. This makes things easier for the renters (and even my wife). Having all the valves and labels identified reduces the pressure on renters to remember everything in that walk though. Then I include tags like the picture that I laminate and place in the relevant locations. The ones pictured here for example I place in the dash with a short list of things to check before moving and some vehicle basics like the height and width. It helps the potentially new driver if they don't have to panic at that low bridge wondering "what height did he say again?".
As simple as it sounds you'll be surprised how much it helps everyone to just spend an hour in the RV with a labeler. I even follow the checklist myself. I can't tell you how many times I forgot that door until the first turn when I heat it slam shut in the back of the RV....