Taking notes
Writing is an essential part of learning. Through writing, we demonstrate what we have learned. We display the ability to think critically. And we develop ideas. But writing is not just the result of learning; it is also the medium. Yes, you write a blog post on a topic you have just learned, but you also write notes to understand that topic better. Those notes that you write when you learn can be valuable. You need to figure out how to take and organize those notes... More here.
Some useful options and use cases included in the above which you may find useful.