get a cheap water pistol (make sure you have appropriate training and licensing). When the cat misbehaves, snap your fingers and then give him a little squirt. The cat will come to associate the finger-snapping with the water. Eventually whenever it hears you snap your fingers it will immediately run, thinking the water is in the air.

Worked for me for all my cats and dogs. I'll bet it would work on toddlers but my wife stopped me when she caught me doing it. I tried to argue referring to B. F. Skinner's "Walden II", but no joy.