How To Professionally Write A Handwritten Letter . A handwritten letter is forever. “i love you,” “best wishes,” “see you soon!”) please sign your name. How to Write a Handwritten Cover Letter in 2020 (With images from www.pinterest.com A handwritten letter is forever. “i love you,” “best wishes,” “see you soon!”) please sign your name. When handwritten, a few things should be included in the letter.