Try not to rely solely on a summary of the candidate's performance in a class or a cursory review of his or her transcripts and résumé. Rather, seek a balanced, detailed, and honest yet favorable portrait of the candidate from your perspective that addresses the criteria desired by the particular scholarship. Feel free to ask the candidate if there is anything that he or she would like you to mention in your letter.
Recommendation letters should be frank and devoid of hyperbole. Avoid pro forma letters at all costs. Letters generally exceed one page in length.
For further help, review sample letters and scholarship-specific information.