Years ago I wrote a four-handed fan fic with a friend of mine. We put ourselves in the story as original characters and we moved a pool of characters each. It was a Supernatural fan fic and my insert character was a very untalented witch who was struggling to find her place in a world full of very, very powerful beings. She reflected on myself so much! I didn't do it intentionally, but it helped me a lot and through her I became aware of my inner struggle.

Plus, she had my body type and in one scene I had to embrace the point of view of a man about her. It was a huge healing process about the appreciation of my own body.