Just read a lot...books, magazines, articles on the web (because most message boards have terrible grammar!).

You will develop your own technique of reading. I can read at close to 800 words per minute while retaining a minimum 75-80% comprehension rate according to the tests I did in a college reading lab. One technique I developed was eliminating words like "a", "the" "to", and other connecting words. However, this technique doesn't work with everyone.

But the best tip is to just read a book. Visit the library. Your taxes pay for it so take advantage of it!