Today I took some time to reorganize my (computer) files, which were in a terrible state.
Back when I was in graduate school, I dumped all notes, drafts, etc., for a particular course into a folder labeled with that course's name. This system broke down a bit once I got to the dissertation research, when virtually everything got dumped into a folder titled "Diss." Eventually this acquired some subfolders ("Drafts" and "Comments", for example). All the research, writing and note-taking I've done since then have not been organized systematically. Sometimes I made new folders, sometimes I shoved files into pre-existing folders, sometimes I left files in the main "Research" folder.
The result of all this is that it has gotten increasingly difficult to find stuff, and every time I look for some particular notes, I end up searching in half a dozen places on the hard drive to find what I'm looking for.
I hope that I've licked that problem going forward. The Research folder now has subfolders for Writing, Research Materials, and Secondary materials, among others, with appropriate further subdivisions. I sincerely hope that making it easier to find research materials will make the time I have for research more productive, and that clarity in organization reflects clarity in thought. We shall see.