I took the GMAT on July 1 and scored 760 (Q50,V44). I'm still awaiting my official score report and AWA scores, but here are the things that I found very useful during my 2-month prep and would highly recommend:
1) At the start of my preparation, I took 2-3 practice tests, treating them as diagnostic tests. I don't think it really matters whose tests you take to begin with, but going through all answers and explanations was beneficial for me since it meant that I hadn't got an answer right for the wrong reasons.This is where I learnt the most about my strengths/weaknesses. This process of reviewing all explanations can be very time consuming though, so I would recommend it only if you have sufficient time in your preparation.
2) I only learnt about the Official Guide midway through my prep, but made it a point to solve every single question and review all wrong answers. This is the best place to practice all types of questions for the GMAT. Also, here's the timing scheme that I used for solving questions in OG11:
Verbal:
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SC - 1min/question
CR - 1.8 min/question
RC - 4.0 min for reading the passage, 1.5min/question.
Quant:
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PS and DS: 1.8 min/question
I initially found it very hard to meet these constraints, but once I could, completing the tests was no problem.
3) Would definitely recommend MGMAT tests as practice towards the later stages of your prep, especially for the Verbal section, which is pretty close to the real thing. The Quant sections have a bit of a limitation in that you can expect a lot of tough questions to show up if you score high, but I found that useful for gaining speed on some of the tougher aspects of quant such as combinatorics, probability etc.
4) Since sentence correction is the only section of the test where you really need to memorize anything, I would recommend the MGMAT SC guide for memorizing the grammar rules tested. It contains everything that you need and nothing that you don't for the GMAT.
5) Would certainly recommend focusing on the GMATprep tests during the last 2 weeks of prep. These are as close as it gets to the real thing and I must thank MGMAT instructors Robert and Mark for this invaluable piece of advice. As someone has already mentioned in the forums, resetting the tests is possible. You can expect about 4-5 questions in each section to repeat, but overall it is definitely a worthwhile experience, although it can tend to inflate your scores if you remember the correct answers! Here are my scores on the GMATPrep tests and they correlate pretty well to the real thing:
GMATPrep1: 750
GMATPrep1(Reset): 780
GMATPrep2: 760 (3 days prior)
GMATPrep2(Reset): 780 (1 day prior)
Hope this helps! Good luck to everyone for his or her GMAT preparation!
best regards,
-Shriram.