In most positive reinforcement classes you are taught to shape the behavior through hand signals before putting a verbal command to it. This is taugh usually with a food lure at first and then gradually faded as the dog demonstrates it knows what you expect with both verbal and hand signals. Both of mine know many hand signals just from obedience training.

Sit - palm down and moving in the direction of the dog
down - downward motion of the hand
come - swinging motion of your arm to your chest
sit pretty - fingers raised in a steady hold higher than dogs head.
give paw - palm up in a receiving fashion.
Back - palm flat in a pusing motion.
directional command - hand flat sideways pointing to the direction the dog is to go.
come to heal - hand in a fist and brought to rest on your stomach.
heal forward - hand motion in forward position and then resting on your stomach.
heal backward - hand motion in a backward gesture and then resting on your stomach.