If it is the policy to fill out an application, do it, even if you already have a resume. The interviewer may need additional information that is requested from the application, or want everyone's history in the same format.
While you are waiting for the interviewer, peruse one of the magazines that are on the coffee table or read the newspaper. Don't pull out a novel from your briefcase. It's fine to read a book at an airport, but somehow in an interview setting it seems out of place. It's better to be interested in business, current events or an industry publication.
When the interviewer comes to greet you, smile broadly, shake his or her hand firmly and address him or her by his or her last name ... Mr. Smith, Ms. Jones or Mrs. Green. Practice handshaking with your friends, avoiding a limp handshake. It may sound silly but a simple thing like a poor handshake can get the interview off to a bad start.