Open the letter with a formal business salutation such as "Dear Recipient" or "Dear Sir or Madam." Use the latter if you do not know the recipient's name.
Explain the purpose of the letter. For example, "It is my pleasure to recommend Janet Lopez as a candidate for Executive Assistant."
Explain the nature of your relationship with the applicant and the length of time you have known him. For example, explain that you are his mentor, coach, supervisor, college professor or business partner.
Summarize your qualifications and briefly explain why a recommendation from you is valuable.
List the applicant's skills, education, training and career achievements that specifically relate to the applicant's field of interest or job request.
Offer an honest assessment of the applicant's potential for success. For example, explain why she would thrive over other candidates.
Provide your contact information and state that you welcome follow-up phone calls or emails, if applicable.