Some pieces of information to include in a friendship letter are your recent activities, your current goals, your hobbies and tidbits about your location. Mention pets and family members and consider enclosing a photo of yourself or your home. Always greet your friend with a polite salutation and conclude with a warm closing, perhaps adding that you will write again or that you wish to see them soon.
A friendship letter is a method to establish a new friendship, including pen pals, or to reaffirm pre-existing friendships. If writing to a potential pen pal, include the return address to make it easier for him to write back. If the letter is to an old friend, bring up shared memories and experiences, such as how you met, attending school together or spending time at work.
Hobbies to discuss often include favorite crafts, books, music, cooking and sports. If either participant attends school, write about the subjects under study. Always ask questions of your friend, giving him content to write about in return. His own hobbies, goals and activities make good topics. Local traditions, culture and upcoming holidays can be interesting topics for discussion as well as an avenue to learn more about the world.