Something that I definitely saw a lot of with the lifehacks research is people smershing all of this - scratchpad, todo list, project info - into one big text file.

I think that’s strongly linked with having text editors that let you jump quickly around from section to section (which mostly means emacs or vim’s incremental search - not sure about BBEdit). Being able to zoom around one document can make it less intimidating than having a dozen different text files, but it can be easily the other way around. Speedy access, and ways of stopping yourself feeling overwhelmed seemed to be the key factors.