There are good ways and really bad ways of studying for the GMAT. Let me give you an example of a BAD way.
The worse way is too take a lot of tests, answer a lot of questions, but not REALLY study. I have seen time and time again people who think that by buying the next best book, they can suddenly gain the insight needed to do better. I have also seen time and time again people who try to do a problem, give up or guess, look up the answer, then say "oh yeah, i got it" then move on. BAD!!!! Worse is people who got it right, but weren't sure, then confirm it is right, then move on as though they somehow now understand it.
If you really want to learn, buy an
OG, do ALL of the questions SLOWLY over time, and do NOT move on until you can explain why the correct answer is right AND why the incorrect answer is wrong CLEARLY and PLAINLY in your own words. This is a long and painful process, but this forum is the best place to practice. (For Q questions, try to be able to solve any problem from multiple points of view. Do NOT rely on memorizing equations, but focus on understanding the underlying concepts).
Once again, when you answer a question here, you should spell out EXACTLY why you answered it the way you did. Moreover, you should not be satisfied until you truly understand backwards and forwards every question you come across.
You will not see as many questions this way. But the ones you do, you will truly understand and that will build your thinking process.
JMHO