Oh god good question. Took me a while to get thoughts together but here we go:

1.) Have idea, yell at friend(s) in dms. This stage can last anywhere from a few hours to a few months. Basically I’ll idea bounce with friends, talk about potential scenes, and pseudo-roleplay. (The roleplay bit applies to original stories too, it kinda just... happens.)

2.) Figure out what the point of the story is. 95% of my ideas never make it to writing stage because I don't have a reason to write it. The point can be simple, like in WoF:when you hit disaster, it can be summed up as "recovery". It can also be more complex like All This History, where the point is answering the question of why Chuuya and Dazai work so well together/seem to know each other heart and soul but also loathe each other. These are solid points that I can tell a whole story about!

3.) Copypaste dm discussions/rp into a word doc and create bulletpoints. Continue adding bulletpoints as I think of new things to add. All my early doc headings look something like these:

4.a) Start Writing. Pick a spot, put words down. Doesn't matter where.

4.b) If it's an especially intensive plot, I'll make a brand new document specifically for an outline. It's a little bit more detailed, has timestamps, and usually revolves around themes or mini-arcs. Here's part of the very first outline for WoF as an example, built around the five stages of grief:

This is basically the closest I will get to a "first draft" because I write stories as I'm outlining them, and I will semi-edit as I keep writing new scenes. Fun fact, the very first bits of WoF that I started writing are what is now chapter 43! Absolutely nothing I do is in order, and that's just what works best for me.

And there's your behind the scenes look at the stories I chuck into the void.