A 530 after just 20 days is pretty good, actually! Most people given themselves 3-6 months to adequately prep. If you're looking for a 700+, you'll need to be realistic with how much work you're willing to put it. It's do-able, but not easy. I'd suggest a test date no sooner than 2-3 months from now to give yourself the necessary time.
A few quick tips:
Schedule your study time methodically. Buy a white-erase wall calendar and write your test date in big letters at the top, then begin to schedule study time for yourself by working backwards. Aim to study at least 1 hour a day, 5-6 days a week. Don't try to cram 20 hours of studying in one week and then do nothing the next. Slow and steady wins the race. Focus, but don't burn out.
Work on creating a strategy for each question type. As you begin to feel more confident with your foundation in content, practice different strategies for each question type. Read articles online at Grockit's blog for suggestions. You may need to try several methods to see what works best for you - make sure you are using your scratch pad, especially for CR and RC. Write down your strategy for each question type as a numbered process. If you can't do this, chances are you don't have a strategy in place.
Use a tutor your weak areas if needed. Consider working with a tutor for a couple hours to hone your technique. Strategy is the most important step in your preparation because it dictates how you are actually taking the test, so if you are struggling with a certain area or question type, you're not alone! Reach out to an expert for supplemental help.
Work on pacing. Don't worry about your pacing until you've reviewed the content and you have excellent strategies with high accuracy. If you try to move too quickly too soon you will likely never move beyond a limited accuracy. Once your strategies are good, try to set an "ideal" time for yourself and practice with different sets of questions.
Take full-length tests. You'll want to take at least 6 over the course of your studies - save the two official Powerprep CATs for the last quarter of your study-time. Use a private company's CATs to practice your pacing and for extra question review but do NOT put much faith in the "scores" they give you. No private company will accurately mimic the official GMAT's scoring algorithm, and too often students are disappointed when they score much lower on the actual GMAT. Don't let these CATs lull you into a false sense of panic or security. Use them only to build your stamina.
Good luck!
