☛ Use the interviewer's first name in the greeting and salutation only if you were told to do so during the interview; otherwise, address the interviewer in a formal manner.
☛ After thanking the interviewer again for the opportunity to interview with the company, affirm your interest in the position and reiterate how you would be an asset to the company.
☛ Add information that the interviewer might be interested in, or some useful information that the company could use profitably. This will help the interviewer to remember you, as most people follow up after a job interview with only information about themselves.
☛ Close the letter with the valediction "Yours sincerely" and proofread it thoroughly for grammar, spelling and punctuation. A poorly-worded or misspelled thank-you letter can be all it takes to disqualify you as a candidate.