SALUTATION:
Dear [TO WHOM IT MAY CONCERN:] or [NAME OF EMPLOYER:]
PARAGRAPH 1:
If it is written for/to
Specific employer: I am writing this reference letter on request of [student] who is applying for the position of [job title] with your [company, school, firm, etc.]
Whom it may concern: I am writing this reference letter on request of [student]. S/he has asked me to write this general letter which s/he may show to any prospective employer who asks him/her for recommendations.
PARAGRAPH 2:
I have known [student] for [length of time] in my capacity as a [your job title] at [your employer]. Also if applicable: [student] worked for me as a [job title]. Or [student] belonged to the [club or organization] for which I served as an advisor. Based on [student's] grades, and taking his/her [excellent, good, etc.] attendance and class participation, I’d rate [students] performance in my class as [rating].
Sincerely yours,
John Miller.