I tried and tried. I spent a lot of time reading passages as fast as I could while maintaining at least a semblance of comprehension. Repetition results in a "feel" for the right answer. Take time to go over incorrect answers to practice questions. Find out why you got them wrong. If you are good in verbal, this does not apply to you (well maybe it does, but I was never good in verbal). I started with a 7 on PR practice tests. I broke 10 on my last AAMC practice test and made a 13 on the real thing. It is possible to improve, you just have to practice like the OP said.