At the Interview
You're there; it's time for the interview! Greet the receptionist warmly and remember his or her name. As a well-respected member of the team, receptionists have quite a bit of pull when it comes to hiring. If candidates are rude, or odd, they'll notice and probably remark upon it to a member of the hiring team.
While waiting for your interviewer, covertly observe the office. Is it clean and comfortable? Do the people walking by smile at you? Are they engaged in conversation with each other? Do they seem to enjoy working there? Do you overhear them talking to or about customers? Is there a respectful, energetic tone to their conversations? This is great information to consider when you are deciding on a job offer.
When your interviewer comes to meet you, look him or her in the eye, give a firm handshake, remember the interviewer's name, and smile! Thank the receptionist (if practicable) as you leave the lobby. Do your best to get each interviewer's card.

