It creates a special moment of interaction with the other person. As you shake hands, push out a positive thought. As silly as it may sound, thinking something extremely positive about the person whose hand you are shaking may actually create an instant bond. Give sincere compliments. Catch people doing something right.
Compliments mean a lot to people.
We shouldn't think that people will consider our compliments phoney or manipulative. People really do care what you think and they really do appreciate your praise. Looks do matter. Charisma depends a lot more on what you do with what you've got than with what nature actually blessed you. Smile for the magic two seconds longer than they do.