I scored 730 (Q50, V40) in my second attempt at GMAT. I got 700 (Q50, V35) in my first attempt.
So here is what i did differently in Verbal:
1. I PRACTICED JUST OFFICIAL GMAT QUESTIONS.
By 'official', i don't mean just official and verbal guides. There are hundreds of questions in gmatprep software; all of them are official gmat questions - enough for a solid gmat preparation. The thing is, gmat is a very standardized exam. There is a specific pattern that is followed. Once you practice enough official questions, you develop a knack to understand what type of errors typically appear, what type of options are typically wrong and how a right answer looks typically. Practicing non-official questions will not only waste your time but also confuse your mind. So refrain from practicing from non-verified sources.
2. I SPENT A LOT OF TIME ON SOLUTIONS
In my first attempt, I focused on practicing more number of questions and never bother to spend time on solutions of questions i got correct. This time around, i made sure i spent 3x-5x time on solutions for every x time spent on questions. So please read the solutions of all questions you solved. There are multiple errors in each option and you always learn new concepts. Also, reading solutions tells you if you got the answer correct for right reasons.
I got the enhanced gmat report and realized that in my first attempt, i screwed up in SC and RC mainly. I joined weekend classes of CrackVerbal and did the advanced documents provided there. Each document has 200-400 official gmat questions with solutions. I didnt do much of CR and finished more than 50% of RC and SC document. Arun, the head instructor there, really helped me at every stage and made sure i move in right direction. So I would highly recommend the classes!
For tests, I did bunch of Manhattan tests. There is nothing else that is closer to actual gmat exam.
All the best