I'm personally a BIG fan of training a dog using his own body language. I find canine langugage INTENSELY fascinating, reading up on how a dog communicates using only his tail or his ears or his eyes. It's fascinating watching two dogs interact, one hyper, excited dog and one low-key, elderly dog. I love it when the elderly dog just gives a look at the younger one and the younger drops the act right away and wanders off to find someone more fun. And when we humans use the dog's natural language to train, the dog understands what we're trying to teach him, so training goes by faster. Like, using the barking as an example, if you yell at the dog or slap the dog, he doesn't quite understand what you want from him. He just understands that you've flipped and turned scary, even if just for a second or two. Now, if you were to quietly, firmly growl, "Enough," he understands your tone and that you're displeased. If he stops, you change your language to give softer eyes, to look away, to lick your lips, whatever. You show your dog that he's appeased you and all is well with the world again.
One method for barking that I've found works (and I learned this from Stanley Coren, a top dog behaviourist who's my FAVORITE when it comes to dog language) uses the method that a mother dog would use for her pups. When the dog is barking, go to stand next to the dog, and hold his mouth (gently) in your fingers, and quietly growl, "Enough." The fingers around the mouth signify the mother's mouth gripping the pup's muzzle, and the growl is, obviously, the mother's growl telling the pup that she's displeased. The pup (and your pet dog) understands that you don't like the noise coming from his mouth, and he stops. This is a good, non-violent, easy-to-understand way to tell your dog the proper way to behave. My dog is sensitive; we used to employ a negative training regime, and it was a disaster, leading to Jake striking out eventually from the stress and fear. When I switched to positive-only, using dog language methods, he calmed down immensely and became much easier to deal with. The thing with dogs is that they're NEVER spiteful. If they do something wrong, it's not because they want to piss you off, it's because they just don't know the proper way to behave. Once you show them what you want from them, they're all to happy to please you and they're eager to obey your wishes. You just have to SHOW them how to do it. They're dogs, not mind-reading geniuses, and like a child, sometimes you have to show them step-by-step how to do something.
On the topic of debarking, I've found that it doesn't even work that great anyways. The dog can still bark; he's just got a raspier, more horrible sound than before.
http/youtube.com/watch?v=d5ZDiDcB1oI