Don't be taking notes during the lecture.
Because then you're not listening to the lecture. It's better to listen to the lecture and then take notes afterward. Of course, that doesn't work for every discipline.
Because what that does is force you to practice remembering. And then, with regards to books, read... Don't highlight, don't underline. I think it's pseudo work.
Read a couple of paragraphs or maybe an essay, depending on the density of the book.
Close the book.
Think about it.
Write down what you're thinking.
Write down what you remember and in the context of what you're thinking about. Because that instantiates it into your memory and puts it at hand.
How it is that teachers or other smart people can remember all the things that they talk about spontaneously when they lecturing. And the reason for that is because they have thought them through. They read them and they think:
-Okay, well that's an interesting idea. How does it relate to all these other ideas that I know? What is its significance for this idea and what's its significance for that idea and do I believe it? How might I criticize it?
So, it's kind of like attaching little memory hooks to it in five different ways. It's part of the mind and that seems to be part of recall rather than recognition. And recall is the spontaneous act of remembering something complex. When you recall something you're actually practicing remembering it. And that's what you need to do if you want that to be part of you. So separate out the function of reading and note-taking.
But don't be like - read a sentence and then write down that sentence. That's not helpful. You could read the sentence then close the book and then reformulate the sentence. So that now it's your sentence.
Then you'll remember it. Then you'll understand it that works really well.