Improving GMAT verbal score

I know this has been discussed a few times before but I still wanted to share my experience and was hoping to get some practical advice as to best way to improve my GMAT score
So i studied for GMAT for 1.5 months give 5 MGMAT and 2 OG practice tests. I focussed on MGMAT books and practice questions. My practice exams I was getting 620-640 till 2 weeks before my GMAT when I realised that I was really not doing well on SC/CR and RC in verbal. I spent 1 week on SC and my practice gmat score went up to 700 with improvement in verbal.
Exam day came and the final score was 620 (Q 48 V 27). I just felt so dejected with my verbal score given that I scored better on my last few practice tests.
Based on my analysis of my previous practice exams my verbal score for all three sections SC;CR and RC is bad with almost same number of mistakes in each.
I am planning to prepare for 1.5 months and retake my exam.
I am looking for advice on how to best practice.This time around I want to change. The SC rules from MGMAT really helped me in the last 2 weeks but I think it was not enough. In terms of verbal conceptual review what books should i stick to MGMAT for SC/RC and CR or anything else.
Also what other books are good for practice for these section.

Thanks