I'm experimenting with a single 500K+ line-long flat text file for EVERYTHING, from dream journalling to work email drafts to blog posts etc. -- I've even copied math from my home whiteboard in latex -- screw rendering, I'll transcribe them back when I need them.

At one point I was trying to do a Luhmann's Zettelkasten with one note per txt file, internal linking, etc. I concatenated every piece of txt content I had. It's much simpler.

I have no system anymore. I try to create internal "hashtags" that are ctrl-F searchable. The goal is having something that's always open and at hand. I got plugins for autosaving when the window loses focus, autoloading when changed in disk and it syncs to Dropbox.

I cobbled together in Notepad++ (which has a GUI for this) a small syntax coloring definition that sort of matches my spontaneous habits from old salvaged text. I intend to let this evolve too. E.g. I'm using {braces} to have a little collapse button that hides pieces of text.