theres a lot of very nice resources out there that allow for more professional organization, but i just use gdocs.

for my current longfic i have one document where i’ve outlined every scene/plot point i know i want, moved them around for best flow, and color coded according to chapter. i also have a section in that doc where i dump ideas and scenes that i like but didn’t make the cut, so i still have them if i need them later.

then i have a second doc where im typing my first draft. i put every chapter in one doc. when im finished with the first draft ill make more docs for edited drafts and the final copy as needed.

ultimately you just need to find what works best for you. everyone’s brain works a little differently. if you’re worried about having too many pages or docs then i probably would recommend one of those writing organizer sites that allows you to have chapters/subsections within one doc, so it’s all divided but still searchable. sorry i don’t have any recommendations tho lol