i used to do the "hunting and gathering" method, where you just look for the answers, and it was a hit and miss process...if there weren't very many inference questions, it worked alright, but if there were more inference questions, it really sucked...and it was very stressful.
Someone suggested a different way to approach RC in a post a while ago, and after using that technique i started getting consistent 22's and 23s across kaplan, topscore, and achiever.
Basically, read the first question. If its an inference question, go to the next one until you find a non-inference one. Then read the passage closely until you get to the paragraph that discusses the topic of the question, and once you finish reading the paragraph, answer the question. Then move on to the next question...
by the time you answer all the questions you'll have read the entire passage carefully and your mind will make a roadmap of where certain topics were discussed, so when you get to an inference question, you'll either be able to straight up answer it or go back to the general area where the topic is discussed.
I don't know...this seemed to work very well for me. Only once did i revert back to the hunting gathering method, and my score promptly dropped 3-4 points and i was mad stressed at the end of the section.
gluck