I'm studying with two main math books (Munkres and D&F) these couple of months. My method so far is just going through the book page by page constructing everything in it (independently if I can) in my notebook. At the end of a section I try to do all the exercise. The ones I don't manage to solve I either post here or save for later. All in all I’m enjoying myself.
My progress is slow (chapter per month) which is not a problem in itself but lately I find myself not remembering things discussed in previous chapters (although I seldom skip any materiel).
Are there any other approaches to reading a math book that anyone could recommend besides the "linear" one?