Sorry guys, this must be the worst thing I can ask on here.. I've searched on Google for a while, and couldn't find anything right. I want to send a letter to Jennifer Lawrence, I found her fan mail address, but where do I write it? On both the envelope, and in the actual letter, or just on the enve...

When asking for an autograph, do I have to send a picture, or can I ask for one in the letter and the person will send it?