My best advice: if you're not scoring 750+, you haven't "finished" the OG. For each and every question in the whole book(s), do you/can you:
1. For quant: know the best, fastest, easiest, and most efficient way to solve the problem? Note that this is probably NOT the way the OG tells you to do it.
2. For verbal: know why every answer choice is right or wrong? Knowing the right answer is fine, but knowing why every wrong answer is wrong is even better.
3. Know what category (e.g., yes/no data sufficiency with plugging in) every question falls into? Can you easily recognize this when you see a question?
4. Make up a similar problem using different facts and/or numbers?
5. Solve that same problem again tomorrow in less than a minute?
6. Explain every problem, the best way to solve them, and why every answer choice is wrong, to someone who is unfamilar with the GMAT, as if you are teaching a prep class?
You aren't done with the OG until you can honestly say "yes" to all of those questions. Until then, keep on studying those problems. Once you can do everything mentioned above, your score will go up.
Jim S. | GMAT Instructor | Veritas Prep
