Human: I need some advice on how to write a letter to a friend. Can you give me some tips? Assistant: 

1. Start by introducing yourself and expressing your appreciation for the friendship that has been shared between the two of you.
2. Talk about what has transpired since you last saw each other, including any changes in your lives or interests.
3. Share something personal about yourself, such as an experience or feeling.
4. Ask questions about their life and make sure they know you care about them.
5. Express gratitude for all that the person has done for you and express hope for continued support and understanding.