One follow-up phone call to the company is acceptable, after that it might seem like pestering.
Send a follow-up letter, if you feel it is required, no matter how badly you think the interview went. Invariably most people come up with a clever answer after the interview has ended, include two or three of these in a letter but remember to always refer to something specific from the interview, eg.
- I've given a lot of thought to our interview and...
- I have been thinking about what you said about...
If you don't get the job
- Look carefully at your interview performance. Try to identify any factors that may have contributed to the outcome, such as lack of preparation or nerves.
- Get as much feedback as possible from the interviewer. Phone up and ask where you fell down and where you might have improved your performance.
- Once you have this feedback and considered the interview for yourself you can modify your interview technique and apply this to your interviews in the future.
- If you feel you would still like to work for the company this is the time to send a letter saying that - i.e. whilst you have not been successful on this occasion you would very much appreciate it if you are considered for future roles in...
- Above all don't be disheartened and don't take it personally