3 weeks left for the GMAT! How do I utilize my time to get a 730+?

Nice job increasing your verbal score. Now, you need just a few more section score points to get to your total score goal of 730.

You should be able to achieve that goal in three weeks.

Your move is to seek to increase both your quant score and your verbal score and get at least one more point in each and, hopefully, get two more points in a least one of the two sections.

For quant, focus on your weaker areas. You can easily determine which areas they are by considering which types of questions you'd prefer not to see when you take the test. By becoming good at answering those types of questions, you can increase your expected quant score by at least a point or two. In the space of three weeks, you should be able to completely master at least five to ten areas of quant in which you are currently not that strong.

For verbal, analyze the questions you didn't get correct on your practice tests and determine what you needed to know, see, or do differently in order to get them correct. I bet that, by simply executing a bit better, you could have gotten a couple more verbal questions correct, and there may be some concepts you are not clear about.

So, fill gaps in your verbal conceptual knowledge and work on executing better to get a couple more verbal points.

For some ideas on how to increase your accuracy, you could read this post. Improving Your Accuracy on the GMAT