Write clearly and concisely. Have someone review your letter before submitting.Learn how to write an employee appreciation letter with these templates and examples. Download the template for free (PDF or Word). I want to congratulate you personally for completing your year with < company name >. It has been a pleasure working with you. Guidelines for writing appreciation letters: State what you appreciate and briefly explain why. Acknowledge the hard work and dedication of your employee with a formal appreciation letter for completing a year of service. Carefully craft your message in a few sentences. Clearly state your appreciation and what specifically you're thankful for.