Begin the letter with immediate reference to content in a previous edition of the publication. Mention the title, writer of the article, and the date it appeared in print. State your support or objection to the article.
Describe exactly what you support or object to in the body of the letter. Be specific in your details and refer to the article or notes you may have taken to ensure clarity and accuracy. Keep the body of the letter concise and full of energy. Make your point strong, with an exceptional point of view supported by evidence. Reference your personal or professional background if necessary to add validity to your perspective.
Include solutions you have for any problems or concerns -- but avoid a diatribe. Keep every part of the letter, from the introduction to the conclusion, as tight and crisp as possible. Send an email or make a phone call to an editorial representative before writing to inquire about a maximum word count. The shorter and more to the point the complaint letter, the better your chances of having it read and published.