Software that’s more advanced than a text editor/word processor has been a big help for me. I’ve tried different apps. Been using Obsidian for over a year now, and I love it. You should find something that works for you, though. It’s a very personal thing. The right one will click with your brain, help you keep things organized, and should feel very easy and intuitive. It should feel fun to use and not a chore. There’s a lot of choices out there like Notion, EverNote, OneNote, Nimbus Notes, MyInfo, and many others.

In my head.

Seriously. I’ve never needed a written outline for much of anything. Even my years long d&d campaigns, and the radical changes that interactive stories like that bring, I don’t have trouble keeping things straight in my head.

The only thing I do keep like that is a timeline of past events as “canon” to keep exact dates in place. I think of it as the inverse of an outline.

If I skip ahead for a section as I’m writing, it’s easy enough to just pop open a second file and make a note for bridging ideas.

I’m not saying outlines are a bad thing, they just don’t work for me. Since they aren’t a necessity, I don’t bother with them. Even with my three ongoing projects, and my slow-ass writing pace, I haven’t lost track of anything yet.