I felt "stuck" in all three subjects until about a month before the actual exam. I made up my mind that in that time I would do what it took to improve at least a point in each section. It worked.
This is ONLY what worked for me:
I purchased the online AAMC material, because it's as close as you are going to get (especially in verbal) to the real thing and after you pay the $80, you own it.
Next step: determine whether or not you know all of the material you need to know for the mcat. This may sound redundant, but every year the AAMC publishes a list of what is likely to appear on the test. Now, some of the stuff that makes the list has a snowball's chance in hell of actually appearing in your exam booklet (T-tests and Chi Square analysis... huh?) But if you've been taking a prep course (EK, Kap, TRP, etc.) then your teacher SHOULD be able to show you what is high yield and what is simply NOT on there (or represented in some abstract and inconspicuous fashion). You are left with a finite amount of material to prepare for in the biological science section in the physical science section.
Next step: figure out each section.
physical science: this is the one that wants to you remember f=ma, the shorter the wavelength equals the longer frequency, and all of those other little equations and tidbits that you can only hope to memorize. Basically, if you know the concept and you recognize what the question is asking you for, you'll get the question right (or not, if you screw up your addition or forget the direction of a vector). For instance, one of the people I was studying with was stumped by a particular question. She had written down all of the variables and could not figure out what the question was asking her. I looked at it and said, "Oh, that's a Young's modulus problem!" She was like "What's a Young's modulus???" There was the problem... Young's modulus appears on that sheet AAMC publishes and for all intents and purposes it's medium yield and usually you just have to plug numbers into the equation... don't need to know much more about it. In another instance, my same friend was spending minutes on a problem. As soon as I said "They're just in a roundabout way asking you for the resultant force," she multiplied mass by acceleration (I think the actual numbers were something like 5 x 10^something and 1 x 10^ something else... three second problem once you recognize what they're asking).
biosci. on the August exam, most of the correct answers came right from the passage or figure provided. Every now and then, they expected you to understand a little bit of basic organic chemistry or to know the difference between insulin and glucagon, but this section was basically a sciency verbal reasoning section with more concrete answer choices.
verbal. In the few weeks before the real thing, I stopped looking at Kaplan verbal. It just didn't cut it. I dove into the AAMC stuff because it is highly representative of the actual exam. I haven't mastered this section, but it seems like the reasoning Kaplan uses and the reasoning AAMC uses contrast just enough to mess up tens of thousands of test takers annually. Kaplan (and presumably other review courses) offer great strategies to adopt early on (at least while you are NOT timing yourself)... this close to the test, however, there really isn't enough time for you to be underlining and paraphrasing and drawing cute, little diagrams in the margins. As with other sections, after you finish verbal reasoning, go over each and every question... scrutinize it to death to see where you went right or wrong, and then redo the passage a week later... and redo it two weeks later. You'll develop a certain mindset that will help you "see" correct choices faster.
And, perhaps the most important thing that I could have done to improve in under a month... a TIME STRATEGY. So many of my friends and classmates thought they would plow through the MCAT without paying attention to the time. There were people at my school who missed three or four passages!!!! They're not going to med school. I suggest you do something sort of like I did:
I grouped passages in each section into time blocks. For example, in biosci, I think I did freeQs1, freeQs2, and freeQs3 followed by psg1, psg2, psg3 and then psg4, psg5, psg6... etc. I gave myself so much time to complete each group and so much time to complete each passage within each group. If I ran out of time, I moved on. With each problem, if an answer didn't come to me immediately, I would give myself thirty seconds to "work it out," and if that didn't happen I would guess. If I still had four choices at the end of thirty seconds... innee, minnee, mynee... you get the picture. I was sure to finish on time and on the actual exam, I had a good ten minutes to go back in the first two sections and a ridiculous amount of time left over in biosci. Also, note that if you ARE able to narrow down your answer to two choices, it is NOT always helpful to go back and make changes... only do this if you were absolutely stumped by a problem, or if you did not have time to do a ridiculously long calculation that was required to distinguish between choice A and choice B.
Good Luck!