The best approach is to not build a knowledge management system for yourself until you need it. When you've forgotten something you need a few times, maybe it's

The best approach is to not build a knowledge management system for yourself until you need it. When you've forgotten something you need a few times, maybe it's time to set up a "common notes" file that you can check first for those things that won't stick. Then when that gets unwieldy, maybe split it into a folder of organized notes with a grep or fuzzy search in front of it (or one of those note-taking apps). When that stops working for you, pull out bigger guns and build something that works specifically for how you use it. By waiting until you actually need it, you skip a lot of the work in maintaining a knowledge base you don't use, and you only build out the bits you actually need, instead of wasting a bunch of effort on things that sound nice, but won't actually help.