If you are working with a recruiter, be sure to call the them immediately.
This will help ensure that the facts of the interview are fresh in your mind. Your recruiter will want to know what your thoughts were, how you felt the interview went, and what concerns you might have. This will also give you an opportunity to discuss the next steps in the interviewing/hiring process if you haven’t discussed this already.
Send a thank you note to your interviewer immediately.
If you were interviewed by more than one person, be sure each person receives a note. Keep it short, but also try to reiterate your interest and your confidence.
Don’t call the employer back immediately.
If the employer said they would have an answer in a week, then aside from the thank you note do not contact them for a minimum of 7 days. Again, being too enthusiastic is not good.
You’re not the chosen one.
If another candidate is chosen, you may send a follow up letter to that employer, again thanking them for the opportunity and letting them know you are still interested in any similar positions in the future.