What really worked for me in terms of boosting my overall score was by reviewing every problem in the OG and really analyzing how the book came to their answers. This really helped me on the SC sections because I started to see patterns in every question. You will also start to develop a catalog of base questions and answers in your mind so that when you do see another problem that's very similar, you can reference your past experience and come out with an answer.
Definitely review each problem whether you got it wrong or right. I always reviewed each question, particularly the SC. Understand how they came to the answer. It will help strengthen your memory. Its almost like building a library of examples to fall back on during the exam.
Do 12-15 problems of SC, CR, RC and Quant questions for 3+hours weekly and give yourself time to focus and review over the weekend with full length practice exams to build endurance. This is an absolute must!!!
Keep pacing yourself. ALways time yourself. GIve your self milestones so that you know whether you need to speed up or have enough time. Its all about endurance. But most of all, you have to be confident. I konw the first time i took the exam, i was a little weary about my abilities and needles to say, the score reflected my lack of confidence. Build that confidence.