Main advice for slow speed stuff is practice a fair bit until you feel ok about it. I try and keep both feet on the pegs to maintain balance, then use a balance of throttle, clutch and rear brake to steady the bike. With practice anyone can do it. I have jusmped on all sorts of bikes over the years, and this works for Goldwings down, but I do understand your situation as those heavier bikes can feel rather daunting - particularly when it is not yours to drop!!
Once you start dangling the feet you start loosing control of the bike, as you need to use its power to keep up the balance. I practice all the time, when leaving the driveway to make sure everything is working, or just playing around in a carpark while waiting for others in a group to get ready.