I gave my GMAT yesterday and could score 680. I felt it was descent improvement from 420 (in September). I never thought my preparation was of 420 during Sept, 2018. I was scoring descent 600-620 in all Manhattan tests. I felt I was giving too much importance to first 15 questions and first RC during my GMAT exam killed my rhthym. But later, I realized that strategy works for people who want to be on 700+ level ( I might be wrong here). My GMAT aim was always 650+. I later learned to time out myself and move on to next questions.
I am not looking to retake again as I need to work on my application and preparing for GMAT has been very exhausting journey for me. I started preparation when my daughter was 3 month. Now she is one year

. It was long journey with lot of breaks in middle (in fact I changed my job too), but I wanted to get GMAT out of my way. I never wanted to have any excuses for not finishing my GMAT.
I am sure their are better debrief around but few things I learned in last months, which I want to share.
-> Solve quality questions rather than looking for quantity of questions.
-> Ace 500 level, then 600 level, then 650 level, then jump to 700 level. I did make few mistakes here to jump directly to 650 level. I was so so wrong here.
-> Solving 2 RC per day. After my disastrous performance in RC in my first take, I decided not to repeat same mistake again. Thanks to project rc butler. I was doing that for 4 consecutive months, (even on weekends). Thanks
workout for having that.
-> Common mistake which many people do. Don't exaust OG resources. I did solved 4 OG tests during my first GMAT exam, when I scored pathetic 420. I also had completed all Manhattan tests.
-> GMAT questions of the day are great. They are actually handpicked and their are always new concept to learn from each question. Please do it
-> Skip your weak areas and focus on your strenghts. This was crucial thing, i learned. Whenever I see assumption, complete the passage, bold CR, I just skip it. I save 3 min their which I can use in RC. I am very slow reader, so need more time in RC to solve questions. I made sure, I skipped atleast 1-2 CR questions per 20 questions. Overall, I got 10 minutes for RC and building my SC accuracy. This strategy worked for me. In fact on my second GMAT attempt, I skipped first few questions intentionally. I don't want to solve 700 level RC and suck my time their. I am happy solving 600 level RC in first 15 questions. (If you want 700+, please dont follow this strategy

)
-> For quants,
GMAT Club tests are great. I did OG material first and later shifted to GMAT Club practice.
-> For verbal, I did enroll for e-gmat. I liked SC course. I did OG material for verbal and then shifted my focus on "only" GMAT QOTD of 2017/2018 (till April) from
GMATNinja. I thought, that was enlightening experience for me. It is quality question with excellent explanation for CR and SC. I learned to look for 4 wrong answers (and not one correct answer).
I want to thanks all verbal/quants experts for being so helpful. Special thanks to folks, whose posts I followed very religiously.
Bunuel for quants and
GMATNinja for verbal.
Please PM me, if I can be of any help to someone. I would be very happy