740Wannabe

Hey Everyone, I'm planning on writing my GMAT very soon and for some reason, I just can't get any better at sentence correction!!! I found the other sections of the test to be fairly straight forward and easy but SC is REALLY frustrating me. I answered the first 50 questions in the OG very well, gave a few wrong answers between 51-70, but since then I have been getting getting waaaaaaaaaaaaaaaay too many questions wrong (almost half of the questions from 90 - 110). Haven't done the rest yet. I've gone through and studied the Manhattan Sentence Correction Strategy Guide, and I know the content well. But I find that as I'm reading the SC questions I just can't quickly identify what's wrong. I'm relying a lot on my ear to tell me when something is up - which I think is a problem. Any strategies or tips? How did everyone else improve their SC? How do you approach SC? Thanks.