Listening. Looking at people, with chin down. Agreeing. Letting the other person do all the talking. Never disagree, people don't need convincing. Always smile, even if you wish to carry a dagger in the other hand, hiding it in your back. Appreciate. Suffer fools gladly.

There are several others. For more information read the works for Robert Greene, Machiavelli, Balthazar Gracian and others.