Write the letter on paper.
Fold the letter to fit your envelope.
Insert the letter into the envelope.
Write the recipient’s name and address on the front of the envelope.
Include the recipient’s apartment/unit number, if applicable.
Add the city, state/province, and ZIP/postal code.
Write your return address in the top-left corner of the envelope.
Affix the correct postage in the top-right corner.
Check the postage amount using your country’s postal rate chart or a postage calculator.
Seal the envelope.
Drop it in a mailbox or take it to a post office for mailing.