How To Write A Letter Head Attention . If you do not know the person's gender, you can write out their full name. The appropriate title to use when writing to a man is mr. What should I put in the header of a cover letter? Quora from www.quora.com Is more professional than miss or mrs, which may appear to be outdated. Here are some steps you can follow to create your letter heading: Demonstrate respect and gratitude to the reader.