QUANT
It is not to hard to push your quant score around 48-49, if you are familiar with Math. But the challenge for me was to push it above 49. I have studied:
1) Manhattan GMAT books
2) GMAT Club Tests ( Like MGMAT, GMAT club also has very challenging questions. )
3) BTG math forum questions. ( There are amazing people in this forum. You might think that you know a subject and the approach to a problem but you will find out many different ways of looking at a question on this forum. When IAN, STUART, STACEY, RON , BRENT or many other amazing people solve a question, it is like a lecture. I followed Cramya's , Mals24, DanaJ, STOP@800's and many other people's posts to learn..Thank you all!)
But maybe the most important thing I learned was:
How to Effectively Pick Your Battles
As Stacey mentioned once, GMAT is like a Tennis game, you will loose some points but you still can win the game. GMAT will throw you curved ball during the test and these curved balls are designed to consume your time and demoralize you.

I realized that if I do not figure out how to solve a question in 30 seconds, I am wasting my time trying to solve it and this is the worst thing that can happen you in GMAT.
Wrong questions take longer!! So not only you waste your time, but you also get the question wrong! - NOT GOOD!
And I learned not to get attached to any question. Do not let one single question to ruin the rest of the test for you. Last week, when I started the Quant I had a crazy DS question as 7th question ( my lucky number!) I started to think:
1) It is one of the first 10 questions. Should I try to knock it down ?
2) Should I risk my time ? Because there were 30 more questions waiting for me and the clock was ticking.
Well, I usually do not pick C or E when I get a tough DS. I looked the statements one more time and realized A is looking better than B and chose A and MOVED ON!
Well this is easy to write but freaking hard to execute during the test. But believe me guys, this is what GMAT game is all about. PICK YOUR BATTLES.
I started to get tougher and tougher questions, but I stayed within my time limits:
5,66
10,56
15,46'
etc...
I did not want to stay more than 4 minutes behind my timing plan, because this basically means that you will have to guess at least 2 questions at the end!
I had 2o minutes left when I started the 30th question and I knew that I am doing good with my time management.
34th question was a combination was a DS question, which combined permutation, geometry and mean!
There was no way that I could solve that problem within 2 minutes. I looked the clock again and looked at the question to see whether I can solve it or not. I again chose my battle! I spend almost 8 minutes and 2 pages and I solved it! I would not do this if this question was one of the first 20 questions.
I finished the section on time and I guessed 2 questions in order to stay with my plan.
Please give it a try:
Manage your time and move on when when you see a question that you know it will waste your time. Just stay with the plan! You will be amazed! [/u]