An important rule in communicating with others is anticipating how the other person will react. Keep asking yourself, "What is my present goal in what I'm saying?"
Be flexible. If your first approach does not get desired results, try another approach. For example, if you are trying to calm someone and what you say increases his anger, try saying something else or speaking in a different tone of voice.
When one strategy doesn't work, try another. This sounds obvious, but it's amazing how often this simple rule is violated. People tend to continue the familiar even when it does not bring them their desired results.
In communicating with another person always keep your goal in mind and ask yourself, "Am I getting closer or further away from my goal?"
(Rabbi Pliskin's Gateway to Happiness, p.263)