Without a doubt, Bette Yip is the best dog behavioral trainer ever.
Bette's use of clicker training to mark the exact spot the trainer desires from the dog.
Clicker training is based on the principle of positive reinforcement. The sound of the clicker is always followed by something (a reward) that the dog wants.
The reward is a yummy treat for the dog. The treat associated by the clicker is the reward, and the dog readily begins repeating the desired behaviors when the clicker is used immediately followed by a treat.