One thing that helps me is to keep a pencil handy and act as if I am noting the book for myself or a friend. So I mark important parts, say "see also <other thi

One thing that helps me is to keep a pencil handy and act as if I am noting the book for myself or a friend. So I mark important parts, say "see also <other thing>" or write little summaries in the margins. This turns the reading into an active adventure and makes me feel more accomplished for reading. Also the next time I pick it up I can get a quick summary of what I read so far by going through my marked notes to get some momentum to read the new stuff!