For technical books, I often try to build something as it goes along, usually not exactly following their examples, but making something slightly different, whi

For technical books, I often try to build something as it goes along, usually not exactly following their examples, but making something slightly different, which seems to require exactly understanding things and not just grabbing the code examples. For math and computer science books, I definitely like to write code to do things. Particularly in math I have the hardest time remembering which greek letter means what thing in which context, and well formed programming language variable names make things much clearer. For other stuff, I try to build an outline of the theory of the book and come up with some actions I can take to see how the ideas would work in the contexts I have available to me. It's a little difficult to take notes depending on the context, particularly with audiobooks. Sometimes I will read other people's summaries to see if I missed something. For fiction and poetry I don't really do anything special except copy down particular quotes I enjoy.