Analyze your fear. Let's say you're afraid to approach your boss with requests or suggestions, and someone is always overtaking you on the career ladder. Look yourself and decide: is there a rational obstacles to the desired behavior? Are there any unpleasant emotions about the initiative? Or are you calm and confident going into the office, and there begins to mumble, unable to cope with the fear at the level of behavior?
Start the study with the rational level. "The enemy must know in person". Learn what you fear. Let's say you are afraid to meet girls. This is a great reason to read books on female psychology, having some fun, watching the weaker sex. Learn everything you can about women and their behavior. This will help to overcome the other levels of existence fear.
Engage the emotional side of fear. Where went your own? Maybe as a child someone you rudely "kicked"? Or a curse teachers was the phrase "are You the smartest?". Forgive these people. Provide them with their rudeness, earthiness and dull fate, she's hardly very friendly.
Practice the desired new behavior. If you have studied the problem, understood how and why any unpleasant emotions, know how to manage them, it's time to Polish the behavior. It will help any communication skills training speeches on friends. Even simple conversations with a mirror or better yet a camera can be useful. Look at the tone, the gestures you use while trying to communicate with you intimidating man. If you work in a group, will receive and analyze feedback. Try new behaviors and get feedback.