With models or adults, I take the pose I want them to take while facing them (mirror image), can get some laughs as I am 300 lbs, over six feet tall, and balding.
Posing family groups - get the adults placed and posed, take a shot, then tell them to relax, bring in the older kids (teenagers), shoot a shot or two, pull in the younger ones and shoot.
One highly challanging shoot I had, posed grandparents and parents (comfortably) then shot as child who was in mid meltdown ran in and out of frame. Got a couple of nice shots and a few blackmail shots for the parents to use on prom night 
