TIP #1: LESS COMMANDING, MORE REWARDING
Dogs who are persistently manipulated with verbal commands, equipment, and physical prompting to perform behaviors (such as pushing them into a sit) become reliant on their pet parents to do everything for them. This is equal to doing a child's homework for him or her.
Dogs, like children, must learn to problem-solve when life comes at them, and providing your dog a motivation to perform behaviors through rewards will help him learn those skills.
TIP #2: DON'T OVERDUE IT
As you train with your dog, it is important that you don't overdo the amount of training. Science has shown that animals retain better when taught in short (five to fifteen minutes) spurts, rather than long, drawn out sessions. Dogs not only fill up on treats, they also get bored during long training sessions. If you over train, your dog will not be as excited about doing an exercise the next time. If you stop before he gets full or bored, leaving him wanting more, you will have a cooperative dog the next time you train him.
Excerpted from Chill Out Fido! by Nan Kené Arthur
Jeff Dentler, CPDT-KA, IAABC-ADT, FFCP, CTDI