A friendly, sincere smile will be passed to others. It not only shows that I like you, I come as a friend, but also indicates that: I think you'll love me. Smile to convey other important information: you should be happy. If you want your smile the friendly feelings messenger, then you must be sent from the heart that smile, in this case, not from the diaphragm, but from the heart of. If a smile is just on the movements of the lips, then there is no need. Remember, not magic influence others, but you their true feelings infected.