There are lots of ways to train dogs and lots of tools with which to train dogs. Please, please, please do your research before choosing a trainer and please, please, please stay flexible in all of your training throughout your dogs' lives. While I believe there is no one way all dogs can and should be trained, there are some definite dos and don'ts for training.
First do no harm. Beating a dog, shocking, zapping or tapping a dog, choking a dog, teasing a dog and/or anything that hurts the dog physically or mentally all have no place in any training repertoire. Dogs are thinking, feeling animals and breaking their body and/or spirit is no way to train a dog. It may make a dog perform for you, but it can permanently damage your relationship with your dog. Do you want your dog to execute a behavior because he has learned that good things happen when he does or because he is afraid of what might happen if he doesn't?
Second if at first you don't succeed, try, try again. Just because a particular training method worked for one dog or even for one behavior for one dog, doesn't mean it will work for other dogs or other behaviors. Never assume your dog is stupid and can't learn. Nothing could be further from the truth! Dogs are very smart and if we know how to communicate with them, we can teach them to do almost anything (that is within their abilities and senseabilities!). Different dogs need different methods of communication and some dogs need different methods from one behavoir to another. Communication and motivation are the keys to dog training.
Last, if your dog will only "behave" for you when he is wearing a piece of training equipment, then I urge you to ask yourself, and answer honestly -- is my dog truly "trained" or has he learned what he can do and can't do based on the training equipment he is wearing? (There are exceptions to this -- elderly people, people with disabilities, people with limited mobility and/or strength, etc. -- sometimes they need to consistently use a piece of training equipment for their own, and ultimately their dogs', safety and wellbeing.) Dogs don't know right from wrong -- it's just not in their mental hard wiring; but dogs do know safe and dangerous. When your dog is wearing a training collar he knows what is safe to do and what is dangerous. I don't know about anyone but me, but I want my dog to do what needs to be done, when I ask him to do it, regardless of what collar (if any) he is wearing. To me, that is when my dog is "trained."
Do your research, ask questions, be willing to put in the time and effort -- dogs are not taught in a day, it takes perseverance on both your part and your dog's. But I can guarantee if you do you will someday find yourself looking into the eyes of not only your canine best friend, but a well-trained, intelligent, bonded companion.