After your interview there are some things to do to reinforce your positive impression and to prepare to continue your job search. Follow-Up Letter
Send a hand-written note to your potential employer. In it, review the important, salient aspects of the employer's business that they felt were important enough to take the time during the interview to tell you about. It will help them realize that you heard what they said and that you took it seriously. Here are some ideas for other things to add to your note: Thank them for the opportunity to interview with them.
Tell them you look forward to hearing from them.
Ideally, you should write this note the same day that the interview takes place.
If the interviewer touched on personal issues during the interview, be sure to ask about them in your note.
Don't try to write the letter before the interview. Self Assessment