What would you look most for in a Lily/Snape fanfic (I'm starting to write one)

It's difficult to know. I've just written one and posted it to this website, that was based on an idea I'd had. Basically I wanted the idea that everything was the same throughout the book but Lily lived after Voldemort came. Then Severus found her and they got together. That's not necessarily what I'd like to read though. I'd like to see him turn away from the dark arts for her. I'd also like to see her forgive him and get together, if this was some parralel universe story like mine. Ultimately you have to find something you can write about! Good luck!