Anything Goes : What make a person seem "professional" by Caroline Boyd

What do you think makes a person you are meeting for the first time seem "professional," (whether meeting them at a gig, an event, or party) and what makes them seem like their faking it? I like to think of myself as a professional individual, but I understand certain things can turn you off from a person; whether it's something they said, their general attitude, or (after working with them a while) how they work with their collaborators. Any advice would be apprecaited.