Prepare Yourself for Writing
Writing an important letter to someone requires advance preparation. This is particularly true if you have an antagonistic relationship with your landlord, or you are complaining about a serious, unresolved issue. Never write when you are angry. Wait until you are calm before writing. If you are writing about an issue covered in your lease or state's landlord-tenant laws, review both before writing. Your letter will be more persuasive if you can cite legal statutes or lease clauses to justify your requests.
Make sure your landlord knows who he's hearing from by including your name and address in your letter. If you are in a building or complex that has a name, use that as well. If you want a quick response from your landlord, include your phone number and email address and let your landlord know when is the best time to call you.
State Your Business Clearly
Clearly explain the purpose of the letter and what action, if any, you want your landlord to take. If you are requesting a repair, state this in your letter and let your landlord know when would be a good time to schedule a maintenance visit. If you are informing the landlord that you won't be renewing your lease, explain this in the first few sentences, then inform your landlord of your move-out date and your new address so he knows where to send your deposit.
Be Polite, Even if You're Complaining
It's easy to get frustrated with a landlord who ignores repeated requests for repairs or refuses to deal with noisy neighbors. Still, it's important to be polite and reasonable. Your landlord may regard rudeness or sarcasm as justification for ignoring your letter or even not renewing your lease. Take a "just the facts" approach when addressing your concerns and requesting resolutions.
Proofread Your Letter and Verify the Address
Spelling and punctuation errors damage the credibility of your letter. Review your letter and read it out loud to ensure that it flows well. Ask a friend or family member to read the letter. She can spot errors that you missed and give you feedback on the clarity and tone of your letter.
Consider Using Certified Mail
Certified mail provides you with proof of mailing and proof of delivery or attempted delivery. Having proof of your communications can be helpful if the situation escalates. In some places, you must use certified mail when sending certain types of letters to your landlord. For example, in Maryland, a tenant has the right to be present at his landlord's move-out inspection if he notifies his landlord of his new address via certified mail 15 days prior to moving.