When talking understand someones emotional and cultural background. In America eye contact when apologizing shows that you truly care, while in Japan they prefer you to duck your head a bit down, use these little things as a "trump" card. If you know someone to be shy and want to make them feel comfortable around you, talk softer and quieter, or if you need to intimidate them (why would you do that I don't know) act confident and look straight at them, talk louder too. If someone is easily temperamental word times when you disagree with them with a positive first. "I agree with you about X that's definitely wrong! But what about..." It's difficult but be conscious of there emotions (are they cocky- praise them before criticizing etc) and think of how to counter them. to get the desired emotion you seek. One thing I will say, don't do it constantly, do it to people you don't know well or if you are comforting a friend, it's best with a deep friend just to be yourself. After all, you are you, not someone acting to be you.