Hi Michael,
To start, with a 680, you're closer to a 720+ than you probably realize - and based on your Official Score, you have the opportunity to pick up some points in both the Quant and Verbal categories. While you might be a bit more comfortable with the Verbal section at this point, it would likely be better for your overall applications if you focused on raising your Quant Score.
Many Business Schools view an Applicant's Quant Scaled Score as an indicator of how that Applicant might handle the 'academic side' of the Program - and a Q45 won't impress anyone. That score implies that you did well on most of the "math" questions that you saw on Test Day, but you made some little mistakes in that section and you missed out on LOTS of 'strategy-based' points. This is meant to say that by focusing on Quant Tactics, you'll be better able to increase your GMAT Score AND better impress how Business School Admissions Officers will view your potential to handle the Program. There are also options to pick up some points in the Verbal section, but with a V38 you do NOT have any big 'weak spots', so we would have to nitpick your practice CATs - and your ESR (if you have purchased it) - to define the little areas that you would need to work on to improve that Verbal Score.
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:
Studies:
1) How long have you studied?
2) What study materials have you used so far?
3) How have you scored on EACH of your CATs/mocks (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) When are you planning to retake the GMAT?
5) When are you planning to apply to Business School?
6) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich