What is unexpected? Note striking or puzzling images, descriptions, words, and phrases.
What forms a pattern? Note words, images, settings, and events that appear more than once, or seem to be related.
How are you reacting to it? Be aware of when you find your mind wandering, when you find yourself getting exasperated, when you find yourself suddenly interested in a way you weren’t a minute before, when you find what you are reading utterly baffling.