How To Write A Good Christmas Letter To Family . This christmas newsletter template is made especially with a family newsletter in mind. By doing this, reading your letter will be so much more. Tips For Sending The Best Christmas Letter Ever! from www.thepinjunkie.com For cards addressed to an entire family, write the holiday greeting, then their last name followed by “family.”. Christmas letters are cheery, express good humor, and attempt to make the recipient of the letter feel joyful as well. Keep your letter to one page of single space, 10 point (or larger) font.