I have two different approaches (really four): two for scientific material and two for non-technical material:
For math/science:
When I'm reading something with logic, I aim to fully understand the material, leaving nothing to the imagination. For instance, if I am given something like computer code, I analyze every step of the code, like it's a big jigsaw puzzle. In the process, I 'put the 'pieces together' visually in my mind, until I get a complete picture of how it works. I insist on getting every step right - at no time in the process do I allow myself to: take what is written at face value without fully comprehending it, skip steps, skip definitions, skim the material, or not read information in parentheses. In other words, every step of the process must be analyzed or I go back to the beginning of the material to understand it.
When I'm solving a problem, I never break the rules, but I will use anything available to me to solve the problem. If I'm allowed to use the Internet, that will be the first place I look. If library books are allowed, I will do a thorough search through the library catalogue to find the correct information. As long as it is within the rules and parameters of the problem, I wouldn't mind if a solution were to simply 'materialize' on the blackboard.
This has allowed me to become a deep learner and a good problem solver.
For non-technical material:
Now, reading a non-technical article is the exact opposite of something technical: at one time, I would try and read every word of a difficult (say) philosophy article, but, when I got to the end, I would find that I didn't have any concept of what I had just read, so I decided to take the opposite approach; I now read just to get the 'gist' of the article, paper, etc. It is not important that I get every word, but it is important that I don't just skim the material either. I try to read every complete paragraph, and if there is (e.g.) just one point or one word I don't get, then that is suffficient to understand the material as a whole. If, on the other hand, there are big passages of the material I do not understand, I either dump it entirely, or go back and reread the material from the beginning; the point is to just get the main idea of what the material is about without getting stuck on details that are entirely unimportant.
Now, in writing something non-technical, I use the opposite approach again; it is now important that every sentence, and even every word be communicated properly. I also believe that one should make their writing as understandable as possible, and therefore appeal to the widest audience. I therefore try to write with absolute clarity. For this reason, I don't mind editing my writing again and again. I do it this way, because I noticed that taking care of the finer details of my writing in school could make the difference even between a 'B' and an 'A.' Therefore, I have developed the mentality that things should be 'dumbed down like crazy' to make them accessible and that 'every detail counts.'
This has allowed me to be decent at understanding the written word, and a good communicator.
Now, how do you learn?