I've been using the
Manhattan Gmat guides to learn materials/concepts and the Official Gmat 2015 for practice problems. The majority of the practice tests I've taken have been Veritas Prep tests. I could try others to see if they would be different, but they have been consistent with my official scores as well. As far as mistakes go, the two areas that are consistently lower than the others have been problem solving and sentence correction. For whatever reason I do significantly better in Data Sufficiency and Critical Reasoning. Reading Comp usually depends on my energy/focus levels by the time I get to it.
Typically with the problem solving there tend to be 2 or 3 types of problems I don't have mastery over (forgot combinatrics/circles in squares etc). Ill study those after the practice test and get more comfortable, then the next test won't ask any of those types of questions and ask 2 or 3 more types that I haven't studied in over a month. As for the sentence correction, the pattern of my errors seems less clear, although there tend to be more verb errors.
I often don't rush to finish sections (for a time crunch) although there are times where I mis-estimate how much time I have or think I've spent too long on a problem and may rush the next couple problems. I think part of the problem is that I'm not spending the correct amount time on certain problems and that I have trouble doing some questions (like sentence correction) quickly. When I go slower and do several sentence question corrections, my hit rate tends to be much higher.
I'm applying to business school this fall (round 2) mostly in December and January. My next GMAT is actually this weekend, which I don't feel too confident about.
Thank you again for the advice. I signed up for a 60 day study plan.