Not Using Computerized Adaptive Practice Tests - It’s important to mimic the conditions of the GMAT when you study. Prep books can be tempting as they advertise themselves as “comprehensive” study guides .
Not Focusing On Your Weaknesses - Some students focus on all sections and question types equally or spend more time on the sections in which they’re already excelling and want to boost their score by a few extra points.
Cramming - It can be tempting to try to shove all of your GMAT prep into the last few weeks before the exam, but whatever you do, don’t try to cram! Studying for the GMAT takes time, a prep routine, and a plan.
Not Getting Enough Rest - Pay attention to your emotional and physical health as you prep for and go into the exam, in addition to your mental preparation. The week before the GMAT, you should still be prepping, but not more intensively than in the previous months.
Refusing to Guess - Some students have a tendency to agonize over GMAT questions they’re struggling with or to take too long on the first five to 10 questions.
Not Taking Notes - Sometimes, test-takers make the mistake of not taking notes on the provided scratch pad as they read a question or figure out the answer. This might seem like it will save time, but not taking notes might actually lead you to take longer.
Trying to Beat the Computerized Adaptive Format - Some students try to guess the difficulty level of a given question as they go along or otherwise try to “beat” the CAT format of the GMAT by focusing more on hard questions than on easy ones.
Never Choosing Sentence Correction Answer Choice (A) - Sentence correction questions provide you with an initial sentence that may or may not contain an error.