This is a link to notes on how to draft an outline that might be helpful. Mind you, this is for Choice of Games specifically so you still don’t have to meet any requirements other than what’s laid out for Hosted titles, it’s not a step by step and it’s from a while ago. However, I think keeping this in mind as a basis could give you a good idea on Steps 1 and 4 which will be the hardest part.
I hope to have the opportunity to beta test your story some day. Good luck :]
Edit: I’d forgotten where I found this so posted only the outline guide originally. It’s from this thread for reference.