Normally I take it very light, still throw punches but with nothing behind them, and for example if I see a wide opening for an uppercut I'll normally throw but not actually make contact and say "cover your jaw". Sometimes you get dickheads that get frustrated by not being able to hit you and start throwing bombs. Then I normally say "watch your power" a couple of times and warn them if they throw hard i'll throw hard back, and if they keep doing it I crumple them with a straight right.
Work on defense, and pop a light jab or hook when their hands drop. Make them chase you so they learn how to cut off the ring, and to build stamina.