To begin, decide what you want to change and find the sources of problems. For example, ask yourself: do you always freely communicate with strangers? Probably not. This situation is also possible, if to determine the true motives of this reason. There are many reasons for fear: the emergence of difficulties for the selection of suitable topics of conversation, fear to seem ridiculous or stupid, small vocabulary, complexes about appearance, etc. Only when you understand the problem objectively, you will be able to find ways to resolve it.
In order for a person to relax and become more sociable, you need to gradually master a means of communicating with other people, both verbal and visual: facial expressions, gestures and body language. Try to make your speech more emotional, exciting and uninhibited. This will be the sign of feedback to the interlocutor and it will be interesting to communicate with you. Remember: the eyes are the mirror of the soul! When speaking do not lower them to the floor, and look people in the eye and observe the stately posture. If you is not very good, you should practice in front of a mirror with his reflection. And more talk, training and developing these skills. This method will definitely help you to loosen up.