I recently decided to write a Alternate Universe Equestria Girls story where Sunset Shimmer is a human hero and Twilight and the Mane Six are stereotypical bad girls. (At least on the surface). So just like in the first EQG Sunset Shimmer has to take on the mean girls and save the school...etc. etc.
Here are a few story notes
.Sunset Shimmer isn't a goody goody but she is a nice or at least honest person in this alternate universe. Oh an she's Human.
.Twilight is a bad girl, but she hides it by pretending to be a sweet studious figure in the school. Sort of like that scene with Sunset and Vice Principle Luna in EQG but throughout the entire story. And it makes more sense with Twilight
.The other mane six are darkened versions of their true selves...not totally OOC but more of you take their already existing darker aspects and amp it up to Eleven!
.There will be a twist at the end but I'm spoiling that. If you REALLY wanna know the twist ending, PM me and I'll tell yuh.
So that's all I got so far, but the problem is I still feel my story is missing a lot, so far I'm only writing the first chapter and that's mostly set up the characters and setting, I still haven't formulated a story, and I still feel my story just hasn't captured as Photo Finish would say...DA MAJIKS! So I need some advice. If you were writing a AU Equestria Girls story in the same vain (Please don't let me writing one stop you!) how would do it and what would you suggest?

This sounds like a really good idea! I'll totally read this story!