Guide me how to write formal and informal letter

Formal Letter:

1. Sender's Address: Write your address at the top right corner.
2. Date: Below your address, write the date.
3. Recipient's Address: On the left, write the recipient's address.
4. Salutation: Use "Dear [Title] [Last Name]," (e.g., Dear Mr. Smith,).
5. Body: Start with an introduction, state your purpose clearly, and conclude politely.
6. Closing: Use "Sincerely," or "Yours faithfully," followed by your name.

Informal Letter:

1. Sender's Address: Write your address at the top right corner (optional).
2. Date: Below your address, write the date (optional).
3. Salutation: Use "Hi [First Name]," or "Dear [First Name],".
4. Body: Write in a friendly tone, share news, ask questions, and express feelings.
5. Closing: Use "Best," "Love," or "Take care," followed by your name.