Your letter of resignation should be addressed to your immediate boss. Mention your intent to resign and the position you're leaving.The best way to resign would be to type a letter, print it, then sign it and deliver it to the appropriate person. This sample resignation letter is available for use on UpCounsel. Read our guide to writing a professional resignation letter that helps you leave your company on a high note. A basic resignation letter should include the fact that you're resigning and the last day you will work.