I'm making this post in the hope that it helps someone with similar score goals. I started with a diagnostic score of V161 and Q161 using the free ETS paper test. I probably spent overall 100+ hours studying in 3 months, solved maybe 500+ math problems and took 7 mock tests.
In general, I felt that the mock tests were MUCH harder than the actual test, so much so that the actual test felt almost too easy.
I think it's also important not to study the day before the exam, and to just rest the whole day before the exam.
I based my math review on the areas I felt I did badly in the diagnostic test. For math review, I used books from Manhattan Prep
to review topics I've forgotten since college: Number Properties, Word Problems, and Quantitative Comparison. I also used the ETS
Official GRE Quantitative Practice Questions and ETS Officin Guide to the GRE. I also solved maybe 400+ math problems
from the Manhattan Prep 5-lb Book of Practice Problems, which was really useful for me. Based on the results from the mock tests, I would focus my practice on my weaknesses. If I had difficulty with inequalities or slow with word problems, I would solve those particular types of problems in the 5-lb book.
For verbal review, I read SAT Critical Reading by Erica Meltzer, which was an eye-opener, and practised using the ETS Official Verbal Practice Questions. But what I felt was the key that really upped my score in the verbal section was not just practising with mock tests
but figuring out for myself why I keep picking the wrong answers. If you understand WHY you were tricked into choosing the wrong answer, and HOW ETS performed this evil trickery, you're well on your way to getting a higher score. Each right answer in the critical reading section has a particular line or text in the passage that makes it right, and each wrong answer may have a particular line or text in the passage that makes it wrong, you just have to find it. In this sense, I feel like the verbal GRE is less a verbal aptitude test and more a find-it-if-you-can-in-the-long-passage-under-two-minutes test.
My scores in the mock tests (all taken within 6 weeks before actual test):
Manhattan Prep Test 1 : V 162, Q160
Manhattan Prep Test 2 : V 164, Q159
Manhattan Prep Test 3 : V 163, Q163
ETS Paper Test 1: V168, Q162
ETS Paper Test 2: V162, Q165
PowerPrep Test 1: V162, Q163
PowerPrep Test 2: V164, Q164
Actual Test: V167, Q165
Thank you to Tommy Wallach for helping me out. I'm pretty happy with the results.
Thanks to Manhattan Prep for their wonderful books.