Just the exercise of doing something regarding the text. Keeping notes in the margin, discussing it with someone, writing a review of the material in long form or in bullet points, keeping track of questions you have, etc. all enhances what you get out of a book. You might resent it as a chore, so you just figure out what works best for you, maybe it's nothing, but trying something different from time to time can't hurt.
My advice is to keep a pencil at hand when you're reading to take a note, underline a passage, or if you don't like writing in the margins, a notebook to the side to highlight things you think are important, things you think are questionable, questions it raises in you, etc.
After that, share it. When you read a section, explain it to your partner, your cat, an internet stranger, to yourself in your notebook, etc.