A dog trainer told me once that teaching beginning handlers to praise their dogs is the hardest part of her classes. Another trainer makes it part of his lesson plan to teach people not only to praise their dogs, but also how to play with them. When I first heard this, I thought it was ridiculous, something like going to a hundred-dollar clinic to learn how to walk. But after I listened awhile, I realized there was value to his approach. All praise is good, but praise specially tailored to connect with the dog's way of reacting is 10 times as effective.
Dogs communicate with one another through sounds easily duplicated by humans.
If you're angry with your dog, for example, dropping your voice to a low rumble will closely approximate the growling of a dog. The woman had a voice that could stop a drill sergeant in his tracks, but when she was praising a dog, she was as sweet as she can be. Try your new crooning voice on your dog, and if his tail isn't wagging within five seconds, go up another octave. Eye contact is one of the most important areas of communication for dogs, and mastering eye contact, dog-style, immediately strengthens your relationship. Catch your dog's eye by swooping your hand under his chin, bringing your fingers back up near your eyes while you make a clucking noise.