I read Building a Second Brain (BASB) a while back and got some great ideas from it (and read The Extended Mind as well, which is a great argument for why you need to spend some time on that second brain, both technologically and socially/environmentally), I believe, but I wanted to point out that there is a playlist on YouTube that takes the idea of progressive summarization and shows how it works, bit by bit. Tiago (author of BASB) shows how he takes notes on his Kindle app, moves them into Evernote, bolds them in one pass, then highlights the bolded stuff in a second pass, then takes the highlighted ideas and creates an outline from those ideas (he’s doing a book summary with a single source, but this can be extended to combining multiple sources of info pretty easily), then writes up his book summary, all while talking through his thought process while he’s doing it.
It’s a 3+ hour timesink, but I found it useful (especially the part where he takes his notes and creates an outline from them) to take the idea of processing your notes from something that you consume to something that you create. (I was about to make an analogy to how the body processes stuff, but then I considered what we create and I decided to spare you all ?)
Anyway, I skipped the shortest video (the one on moving your highlights from Kindle to Evernote) because I already have a process that takes my highlights from Readwise Reader, Kindle, and Medium and puts them into my favorite note-taking app (Tana, by way of the Readwise Obsidian Plugin – crazy manual process, but valuable!) and I really stopped paying attention in the outline to output video, because I have some experience doing that, too. The outline video, though, really gave me some great ideas on how to use the notes I have from my reading to help fuel my output here, at work, in my presentations and articles and in the classes I teach.