Writing a letter of recommendation is a big responsibility. If you are writing a letter of recommendation, it can be done easily. Just keep in mind to be friendly, informative, honest, and are specific with the information given. Also try to anticipate what the interviewer will ask and leave your contact information for further questions.
The header of the letter should be simple and easy to read. In the upper left hand corner of the letter should be your name, address, and the date. If you would like, you could place your business title below your name. If this is letter of recommendation is for a person going for the interview within the same company you are in, then placing your title would be best.