While the GRE exam is on your head, you're trying various tricks of the trade to complete the syllabus, most of all mugging up the vocabulary. 

 Dont try to cram up things before your GRE test date. If you want a good GRE score, you should not be panicky. Stop preparing 2 days before the exam and just relax, play some sports, watch tv etc. 

Start preparing at least 3 minths before the GRE test date. You can join a coaching centre, or study with gre tutorials available on the web. You will find a good amount of study material for GRE, and some even for GMAT from my blog. If you ever forget its link url, you can always make a google surch for "gre ghost" and you will be able to access my blog from the surch result.

 If you just study from verbal from Barrons and Quant from Nova, you should be able to get a decent score. Also check out the vocab enhancing software like vocaboly and wordhacker, all available on my blog for download. 

All the best!