I read enough that my biggest problem is remembering what I’ve read.
I’ve long had the habit, when reading, of marking interesting bits of text with a Post-It flag. This is quick and makes finding and re-reading the parts I found significant easy, but it’s only a partial solution; sometimes I cannot recall what I was thinking when I chose to flag a certain phrase or paragraph. That is why it is so important to take notes.
My notes are not simply paraphrases of the text, but include context. Where appropriate, I expand on what I’ve read with my thoughts and opinions and links to other sources.