Hoping that my experience will prove helpful:
Like a lot of plp have already mentioned, having basics in place is half the battle won.................especially inequalities, /X/, and coordinate geometry ....................a lot of basics can be learnt by looking up concepts on google's site................it's very very imp to study concepts................Club challenges have some of the toughest q's and wat is more important is that all the challenges are timed.............even if you're able to solve a 17 challeneges............it is still good enough........and tht's not all.............one has to review each challenge by going through both q's where one would have gone wrong and those q's which one would have got right.................since at times there is more to a Q than what we presume or assume.................Solving as many problems as possible on the math forum is probably the best prep tool..................that apart one should try to cover each and every problem from teh Gmat prep by installing and re-installing the software, so that one comes across all possible Q's...................most imporatnt of all is doing timed tests...............this is the only way to practice Math.........................initially one might make a lot of mistakes in the Gmat prep CATS..................which is okay................The more number of silly mistakes one makes on practice tests the more careful one would be on the actual GMAt test.....................atleast taking 12 GMATprep CATS a 3 weeks before the exam (Timed tests) is enough preperation............Have an
error log................every question that you would go wrong in, please try solving it again at a later point in time............just to make sure that u still remember how to solve stuff......................revise........revise and revise...........atleast a 3 to 4 times................i twill take a lot of effort, but will pay off in the end................every time you revise try solving the problem as if it were a totally new Q...........................The Problems on the real test more often than not are very tricky rather than them being tough.....................they seem tough because they are tricky......................My math skills are nothing close to being good......................but i knew that no matter what i coudn't really bank on my verbal score................which is why scoring well on math was priority for me......................one cannot afford to get complacent thinking that one’s math skills are good………………..what matters is pratice under timed conditions……….that is the only way to do well under test conditions………………The test conditions rule one's score..................and doing well on the first 15 to 20 Q's is crucial, even if it means that one has to spend more than the usual 2min/Q ...................Kaplan CATS are also very helpful............some of the math q's in kaplan's CATSare tough to solve under timed conditions...............but reviewing the solutions for all the questions in those CATS helps one pick up concepts ................................scoring between 41 and 44 is not so difficult.................but anything beyond a 45 needs careful attention to every detail while doing the real TEST...............The GMAT does not test one's prowess in knowing formulae.....................but knowing formulae is equally important.....................they come in handy when one is grappling with time issues..........
PS- Before looking up solutions, one has to try solving Q's on one's own............for all you know, you might just come up with a new shortcut or an easier way to solve the problem............