Those are always there, and I can go back to them and look stuff up even when it's otherwise lost. Then, I've got timelines and timetables showing what happens when in the story. I've spent a while monkeying around with three-ring binders, in which I glued pages here and there trying to figure out how to sequence things. It's a big mess. It's a big pile of stationery. Many trips to the office supply store, and many failed attempts. But in the end, as long as you can keep it in your head, that's the easiest way to manage something like this. You can move things around inside your head more easily than you can shuffle papers or cross things out on a page and rewrite them.