Maria Popova, writer, blogger and critic and better known for BrainPickings.org reveals her note-taking system while she reads all her books.
In order to memorise and remember the pattern of the writer’s thought and the most important topics and ideas from a specific book, she does the following:
1. Create an Index at the beginning or end of the book.
2. While reading, add topics and ideas with the relevant page.
3. Use or create your own acronyms: Maria uses “BL” for beautiful language or “LJ” for Literary Jukebox (a little side project of her).
A small piece of advice that makes it easy to recall the topics and main ideas in each book, even if read a long time ago. Just go through the index and you can easily catch up on what was the book about and find relevant pages.
Listen to her whole workflow and workaround in this talk with Tim Ferriss.