I use OmniOutliner. Before that, existed, waaaaaay back in the early history of the Macintosh, I used Dave Winer's MORE outliner. So I've been using outliners f

I use OmniOutliner. Before that, existed, waaaaaay back in the early history of the Macintosh, I used Dave Winer's MORE outliner. So I've been using outliners for the described purpose for more than 30 years. Using an outliner has always worked, for me, as well as I could possibly want. BUT there is one trick I use that makes a huge difference. I embed keywords into my outlines. I use words starting with underscores (I started doing this before there were hashtags; now I would use the hash symbol). So a headline might have a keyword in it, in which case I can instantaneously find it. On the mac, I can even use Spotlight to instantaneously find a keyword in whatever outline it may appear in. Also, for subordinate subjects in subheadings, I embed sub-keywords starting with *. (The same sub-keyword might appear several times in an outline, under different main keywords.) This technique empowers me enormously in saving all kinds of notes, links (to the web and to on-machine files), etc. and being able to get to any one of them almost instantaneously, even if I don't remember what outline it's in (which is rare). One advantage to using outliners is that there's a common format, OPML, that most outliners can import and export. So if the product you're using dies over the decades, you can just switch to another one. I highly recommend this technique.