Timing Yourself
 
Picked this up from one of the GMAT prep sites.
 
"..Before starting the test, I made two tables in my scratch paper. One for QUANT and another for verbal. For QUANT, I wrote from 1 to 37 on one coumn. Against it wrote from 73 to 0 decreasing in interval of 2 (73, 71, 69 ...). The idea is whenever I want to know the time I am lagging, I have to see the time from the table across the question number and compare it with the time remaining. Though I was prepared like this, I took too much of time for first ten questions. In the midst of test, I was lagging by 15 minutes and could not help but guess for five questions.
For verbal, my table was as below.
0 - 75
7 - 63
14 - 50
21 - 38
28 - 25
35 - 13
41 - 0

I cultivated the habit of checking time for every 7 questions and it really helped me in the test..."