My procedure is similar to Toms but applicable to my particular set up. I always do it in the same order, always. If I get distracted by a visitor, or a question from the wife I stop, take care of the distraction and start at the beginning, check the pins, check the locks, etc until I get to the step that I stopped at.
Park car behind motorhome in correct position to hook up, leave engine running, in park, take gloves from drivers door pocket
Extend drivers side tow bar arm set on baseplate, extend pass side arm set on baseplate
Pin drivers side, secure with padlock, hook safety cable
Pin pass side, secure with padlock, hook safety cable
Take brake hose and light cable off Guardian shield and connect lights then brakes, put brake fitting plug on Guardian arm
Pull Guardian pin on pass side, pull pin on drivers side, step into middle of tow bar lift Guardian shield off MH put onto car, replace pins.
Visually look at tow bar pins, cables, air hose and light cable, look at hitch pin and MH end of cable and hose
Inside car, turn off engine, turn key to acc, put trans in N
Remove fuse cover, flip tow switch from run to tow
Remove, with quick release keychain, all keys except ignition.
Put gloves back in door, close and lock with fob
Look down drivers side of MH, look at drivers side car tires
Walk around back of car, look at 4 way flashers flashing lights on car,
Look at pass side tires, look in window to confirm Neutral, look at towbar pins, locks, cable, hose from other side.
Look down pass side of MH
I also look at the first turn to see the tires on the toad rolling and front wheels turning properly in mirror.
I can't overemphasize the importance I put on always doing it the exact same way. Unhooking also is done exactly the same every time. A different sequence but a memorized rote sequence done the same every time. Maybe it's wrong, but it works for me.