saurabh, the first thing I would suggest you to do is go through the "best of verbal" forum. Go through every question there and see what the explanations are and do not worry if you get many of the questions there wrong; they are of higher difficulty level. Next, go through the OG (again if you already did) and analyze EACH question in excruciating
detail. And I DO mean it. You cannot just do all questions in all books without understanding the concepts being tested. As I many times repeated, verbal concepts in prep books will teach you the basics like parallelism, verb tense/pronoun agreement, misplaced modifiers, idioms, etc., but it will NOT teach you second order things like clause vs phrases, parenthetical elements, ellipsis, run-on sentences, restrictive vs non-restrictive clauses, introductory modifiers, etc. There are MANY threads on second-order learning for SC in this forum, especially in the "best of verbal" forum.
As for CR, you should learn to recognize the different types of flaw patterns. By doing many of them and being able to explain why one reason is best and how each of the other reasons can be refuted
, you will inevitably get better. This is the ONLY way to get better in verbal. Once you can be good enough to teach those concepts in your own words, try to take the GMAT again and I will guarantee you that the verbal score will be better.
Remember, there is no easy way. The ultimate result will depend on rigor of your study habits. Last but not least, participate in the discussions. There is no merit in getting an answer right. Instead, one should explain HOW he got it right.
Good luck and welcome to GMATclub.