RC - Read each para and write the gist. And just note down the purpose of each para. Do this in all the practice tests.
CR - I read PowerScore. But as I said before , I could not improve on it much. I would suggest practice under time constraints and use error logs to track common mistakes.
My GMAT prep was 680 before I started the prep. 730 before my exam.
MGMAT was 700 , 710 , 690.
I had some old Kaplan tests. That score was horrendous around 630 - 640 I think. But their old tests was ridiculous.
Per section it was very hard , it was hovering all over the place. In one test I got 13/15 RCs correct and half of the CR wrong. The reverse has happened as well. When it came together I had around 8 errors in verbal overall and it gave me a score of 41.