All the debriefs that i read of successful GMAT-beaters, recommend keeping a log of all the wrong answers while practicing. I never realized the significance and value of this until today. Yes, i had been keeping an Error Log and have logged all the questions that i got wrong while going thro' the Official Guides.
This week I started to re-visit all those questions that i got wrong. Surprisingly, i found that while redoing all those questions, i made the same exact mistakes as the previous time especially in the SC section. Then i went back and reviewed the answers and this time i nailed my mistakes. I now know for sure the reason that i picked a wrong answer and this knowledge is very very important. I repeat the knowledge of why I picked the wrong answer is extremely important. I also know for sure that in future i would never make the same mistake - after two times you gotta learn from them right?!!
I would have made the same darn mistakes if i faced those question in the real test. But now thanks to this excellent tool i would never again make those mistakes again!!!
Here is how i made an error log. I took a spreadsheet and made four columns and named them Question number, Reasons for mistake, Re-take - Correct/wrong and Comments. I created 4 similar spreadsheets with the same columns and logged in the data every time i solved a set of questions from the four sections - PS, DS, SC, and CR.
Hope this would help others in their prep too.