Hi vnguyen74,
With a September 10th Test Date, you have about 8 weeks of potential study time. It's not clear what your Score Goal is though, so it's tough to say whether you might achieve that Goal in this timeframe or not. In addition, the GMAT has gone through some changes since you last took it (the Quant and Verbal sections are now shorter - fewer questions and less time), so you will have to train to properly deal with the new 'feel' of the Exam.
Before I can offer you the specific advice that you’re looking for, it would help if you could provide a bit more information on how you've been studying and your goals:
1) What type of studying have you done since last August?
2) What study materials have you used so far (including before you took the GMAT last time)?
3) Have you taken any practice CATS in the current, shorter format - and if you have, then how did you score (including the Quant and Verbal Scaled Scores for each)?
4) What is your goal score?
GMAT assassins aren't born, they're made,
Rich