The question was posed on a site dedicated to discussion of programming and related subjects. It therefore should be assumed that the author was requesting advice for developing abstract reasoning skills such as are employed in mathematics or software engineering. Your suggestions require explanation as to why they would help this sort of abstract reasoning. As a matter of fact, many people who are proficient in the skills you mention are hopeless at the type of abstract thought used in math and computer programming, so the skills you list are certainly not sufficient. Most of them are also not necessary (all apart from writing and reading challenging literature?).