:them: the only time I strap it down is if I'm removing a wheel.Position them so that both wheels leave the ground at the same time. If you are going to remove a wheel, exhaust, or other heavy item, adjust accordingly and consider blocking at the lifted height before removing the object.
A good place to start is to position the rear rubber pad just 1" behind the rear frame bolts. Your balance point may vary.
I don't use the straps. I was nervous about it at first, but not any more. I'll lift my bike to full height and wash and scrub tires without fear now. Just remember to check to make sure that your jiffy stand is extended before you lower the bike.