I write totally out of order. I write whatever scene, chapter, vignette, etc, is in my head at a given time. And I’m one of those weirdos who writes longhand, to boot.
After I write everything down for today, it goes in the “to be typed pile” for tomorrow. Then, I take the completed chapter printouts (and only after the chapters are “completed”) and put them in page protectors in a 3? binder. This becomes my “working copy” where I can scribble notes, ask myself questions, write more information/scenes/dialogue etc in the margins or on the backs of the sheets.
The revised, completed copy I make from that “mess” becomes the “readers draft” which goes out to my first readers. 😉