One old joke said that the first and most important step in training a dog was to make sure that you were smarter than the dog, the implication being that you should train the dog instead of the dog training you. This is not a joke. It is a reality. At the time of writing this my best friend is letting her puppy train her. I cannot convince her to train the dog instead. She is otherwise very intelligent.
Until a few years ago most people believed that to successfully train a dog you had to be harsh and tough, to show him who was boss. There were several difficulties with this philosophy. Often the owner would pay someone else to train his dog. Then the dog would obey the trainer out of fear but would not do anything for the owner because he was not afraid of the owner. Many people felt kind-hearted and chose to let the dog do whatever it wanted instead of harshly training it. The result was that the dog was totally untrained and became a nuisance to the whole neighborhood. In extreme cases one of the neighbors poisoned the dog.
Many modern trainers have completely rejected this concept. They have discovered that in general dogs do not completely understand the concept of being punished for doing something wrong. They either become confused or believe that the person doing the punishing is just is a cruel person.
A person using the old philosophy would hit or kick a dog each time it barked in the house and it would take a long time and a lot of hits or kicks before the message got through. An intelligent owner is more likely to simply turn his back when the dog barks. The message gets through in a very short time. He will praise the dog when it relieves itself at the correct place instead of punishing it for relieving itself in the wrong place. This often will decrease the required training time by anywhere from 50 to 75%. The concept is that the dog should be doing whatever it is that you ask him to simply because he wants to please you. This can establish you as the leader of the pack. Pack psychology is still present in modern dogs, although they are probably a few thousand generations removed from their ancestors, the wolves of central Asia. I cannot explain why a dog will accept a human as the leader of its pack but this seems to be the case.
Dogs can be trained to obey a wide variety of verbal commands and/or hand signals. Some have reportedly learned as many as 200 different tricks. These are usually taught to the dog while it is playing with its owner. If this is done properly the dog looks at the lessons as simply a part of a game. The owner either says the key word or makes the key gesture and the dog follows along by playing its part in the game. In effect the dog is working with the owner instead of against the owner. The more the dog learns the better it likes the game. In one extreme case, I have seen a video of a dog dancing a merengue with its owner. The dog appears to really adore its owner. The commentary that I saw with it said that obviously the dog was very well treated to adore its owner so much. I have to agree.