I do not read non fiction regularly. And when I do read it I don’t approach it any different than my fiction, unless it’s for a research project. Being a historian I do read non fiction but it’s not something I work into my general rotation. When I am doing a research project obviously I will pick books for that topic and generally pick it apart for what I need. If I am reading it just for pleasure, I pick whatever jumps out at me at the time.