For books, something that has helped me in getting the best of the stuff in them has been this. For every new book, create a google doc with three sections:

1. Before 2. During 3. After

The first "Before" section is to list down your preconceptions about the topic you're going to read about. What do you think you already know about the topic? What do you feel about the topic? And so on.

Next, as you go through the book page by page, contrast whatever you encounter with your preconceptions. Is there anything new or interesting there? Actively seek interesting-ness or novelty. Or is there a fact that contradicts or supports your preconceptions? Note all of those down.

And once you're done with reading, spend some time listing down your thoughts in the "After" section. Have you become wiser due to the book? Do you feel better at knowing more? Have you clarified your understanding of the world or yourself? Or at least, do you have more questions on the topic with you for further study?

If you have additional time, restructure everything you store into a blog-post. I modified this idea originally from Farnam Street (https://fs.blog).

In the long run, this sort of delta-maximization framework can become powerful and addictive and a great addition to your life.