Communication is a matter of interaction and understanding between two or more subjects of a verbal and non-verbal nature. This is the theoretical rationale for the interaction. But in practice, these 4th principles will come in handy.
1) The first and main principle of communication with people is the realization of a simple truth - criticism is useless! People are basically not used to condemning themselves, because life passes and, if you engage in condemning yourself personally, you can miss, plunging into your world, many memorable moments. What to do in order to at least somehow influence the behavior of friends and relatives, if not to use criticism? Everything is very simple! Instead of condemnation, good behavior should be encouraged. This can be done in a variety of ways and all of them will act many times better than any criticism.
2) The second principle that needs to be learned is how to properly achieve the desired action from another person. The truth is simple - in order to persuade another person to do what you want - you need to make this person also want to do it. How can this be done? You need to offer what he wants. Ask yourself more often the question: "What, exactly, does this person want?" and then you will receive a key to his heart and behavior.
3) The great philosophers argued for a long time about the reasons that control our actions, and they all came to the conclusion that one of the main reasons that awaken us to action is the desire to be significant. Give people the opportunity to feel significant, and you will get a mountain of friends and pals.
4) The last principle, but not the last in meaning of communication, is "Show sincere interest in everyone." If you are interested in people, they will be interested in you. If you praise people who you think really deserve praise, they will love you more and more every day.