Here are a few things you need to keep in mind while revising from the
OG.
1. Solve ALL Questions:
A lot of students get fixated on questions they got wrong the first time. Remember there are a lot of reasons why you could have gotten those questions wrong. For example, it could have been a silly mistake (maybe you overlooked a decimal point), or a concept that since then you have been able to understand well. On the other hand, a particular question you might have gotten correct because of a random guess or a fluke. So make sure you are solving both the right and the wrong questions.
2. Focus on takeaways:
Do not try to remember what you did the first time or whether you are able to recollect the approach or the answer. Instead focus on just trying to apply whatever strategy you would use on the GMAT onto that particular question. Focus on each question and ask yourself this: What about this question can I use on the GMAT? Because you are doing it for the second time, the chances are that you might be able to do it faster - that is okay - what is more important is to see if you are able to see a difference in the way you are approaching the question. You are not just solving it, you are just looking at takeaways from that question.
3. Don't solve all the questions:There are plenty of official questions to solve so don't spend way too much time on this exercise. For example you may choose to skip certain sections that you are confident about. Or you may choose to start only from question number 50 (because the questions are graded from easy to hard). Also when you read a question you remember very vividly - just move on. You should ideally not take more than a week for this whole "revision".
Apart from this, also treat each section differently.
1. While solving PS ask yourself if you were able to backsolve or use any other shortcuts for finding the answers.
2. For DS you may want to have your swiss army knife of values to "plug in" ready for testing.
3. For SC you may want to see if you are able to grasp the overall sentence structure, and use multiple errors to solve.
4. For CR you may want to see if you are able to use the negation rule in assumptions, or the 100% truth rule in inferences.
5. For RC ask yourself if you were able to map it correctly (just enough to get the gist), and if you are able to identify the traps in the answer choices.
If you are able to do the above then you will see a marked improvement in the way you are able to solve NEW questions.
If you see yourself struggling with the same issues then perhaps the way you are analysing the questions needs a relook.
hope this helps,
Arun
EDIT:
Adding links for
OG explanation & why the explanation suck :0)
https://gmat.crackverbal.com/free-resour ... o-library/https://gmat.crackverbal.com/gmat-og-explanations/