I suggest doing more practice tests and looking at your mistake pattern. Some of the tests (like Kaplan) after a test give you mistake charts, which in my case were very close after each test. I tried to work on those problems. Simply practice more and look at the mistakes. Also check where are you making more mistakes in DS or PS. If lets say, all your mistakes are in DS, work on that. Another case, which is mine

, are stupid mistakes and not paying attention at what is being asked. But things have been like that since I was maybe 7, so I'm working on that. GMAT likes to play those tricks, like ask for distance of round trip, if question is in minutes answer choices are in hrs, etc.