Ok so I know a few of you are groaning right now but here me out we all know that when we first started writing all of us had at least on character who was a Mary Sue thing is lately just about any original female character is labeled a Mary Sue and not all of them are bad even the ones who are a blatant self insert by the auther the trick is knowing how to do it. So here's the deal write a fic about the boys but add yourself, your family and your friends. Write about your hometown and a local ghost story or supernatural legend. You can change the names of yourself and your family and friends but leave everything else as it is then write what you know and see if you can weave Sam and Dean into your life and not the other way around. The end result watch Mary Sue become a solid OFC.