The safest initial approach with rabbits is to begin by stroking the top of the head. Do not offer your hand for a bunny to sniff the way you would to a dog, because most seem to find this gesture offensive and may attack (lighteningfast lunge with a snort). Most buns also do not like having the tips of their noses or chins touched. Their feet also tend to be ticklish.
Often a bunny can be "hypnotized" by cradling him on his back in your arms or across your lap, tipping the head backwards until he's "out." It's helpful to do this when cleaning bunny's sensitive areas, like the face. feet, or under the tail. If the hind feet seem to be vibrating, touching them will stop it.