In my experience, every lecture I repeat for a different class gets better because explanations improve with time. And every doubt from a student which I cannot answer impels me to search for a deeper understanding. This is close to the Feynman technique.
People knew Richard Feynman by his simple and creative explanations for complicated subjects. And I think we could apply his technique to improve how we learn anything.
Step #1: Pick a topic interesting to you and study it
Whoever has a curious mindset always finds something interesting to understand better. But those who are less curious can always pick something intriguing they encountered during the day.
Step #2: Pretend you teach what you studied to someone
My kids do this every time they study, and we can do it too. Or, better yet, try explaining what you’re studying to a friend over lunch. If he doesn’t understand anything you said, then you have to make the speech simple. And simplicity is essential in this step.
Step #3: Back to books when stuck
If you fail to provide a simple explanation to someone, it means you haven’t yet understood it. In this step, going back to books has a specific purpose. You know where you’re stuck. Thus, you need to find that missing link.
Step #4: Simplify and sketchnote
Overcoming when you get stuck means simplifying your explanation even further. In this sense, an image is often worth a thousand words, and sketchnoting is an excellent skill to improve how you explain anything. Ultimately, it improves how you learn.