Greetings!
If you have landed up on this post after seeing the title, it is highly probable that either your GMAT mock or your recent GMAT attempt landed you somewhere around 640. Don't worry. I have been on the same shoes.....demotivated, frustrated and yet searching for a similar story just to get that ray of hope that it is still possible to crack the test. Yes it is possible! No doubt about it! But what's important is for you to dust yourself off, get back on track and keep the fire alive.

Here goes my journey from a 640 to a 730! If I can, you can too

My target score- 700/710
Target split- Q49 , V37/38
Attempt-1
Date:21 April 2018
Score:640(Q49, V27, IR7, AWA5)
Preparation time:December 2017 to April 2018 interspersed with times of no practice at all.
Study Materials used:[*] OG 2017 - both quant and vebal
[*]
Manhattan Books- both quant and verbal
[*] Free questions available in Veritas Prep- Verbal
[*]GMAT Prep mock test.
[*] Free mock test from Manhattan and Veritas Prep.
[*]Free Webinars offered by eGMAT - both quant and verbal
[*] Free eGMAT Quant Workshop
[*] AWA- picked up a standard template from GMAT Forum and stuck to it. Practiced 3 to 4 essays from OG and timed the essays.
Approach:[*] After having completed OG and Manhattan, I realized that my quant is good enough, but that I will need to put in a lot of effort for verbal. So after a point I started concentrating on verbal alone.
[*] The target was to reach the answer somehow. The method of approach didn't matter to me, may it be quant or verbal.
[*] No particular strategy to solve questions.
[*] While covering the modules in OG and Manhattan, I prepared notes for myself, which I referred to on the night before the exam.
The Exam:[*] Order of attempt: Quant, Verbal, AWA, IR.
[*] I was pretty stressed out, especially for Verbal.
[*] Felt quant to be a bit hard, but was happy about it since that indicated that I was doing well
[*] Verbal turned out to be a mess. In a hurry to finish the sections, I wasn't able to read the questions properly. Blindly attempted 2 to 3 questions in a row without even reading the questions. One of the RCs was so hard that I couldn't make out head or tail of it. There goes 4 questions down the drain!!!
[*] IR and AWA were decent.
What went well in this journey:[*] Came to know the general pattern, my strengths and weaknesses.
[*] An experience of eGMAT through their free webinar.
[*] Got a clear picture of where I stood.
[*] Got a feel of what GMAT feels like.
[*] I had given my mock tests on glazed writing pad. This helped me get the feel of writing on it and I did not face the problem of getting accustomed to the writing pad during the actual test.
Attempt-2
Date:14 July 2018
Score:670(Q49, V33, IR5, AWA4.5)
Preparation time:April 2018 to July 2018 interspersed with times of no practice at all.
What I realized from my previous attempt:[*] I purchased the ESR for my previous attempt and thoroughly analyzed it. It gave me a clear picture of my poor time management, my consecutive mistakes and how poor I was at Verbal, RC in specific.
[*]Time management is very very important.
[*]I need to put in a lot more effort in Verbal.
[*] I'm pretty good at quant. But if push a little further, I might be able to touch 50.
What I did differently from my previous attempt:[*] Enrolled for eGMAT Verbal Live Prep.
[*] More organized study- thanks to eGMAT. Their 3 step process worked like a charm!
[*] The goal was to follow the right approach to arrive at the answer.
[*] If I got a question wrong, I made sure I understand why I got it wrong, what made me choose the incorrect option, what makes the correct option right and why is it different from the answer I chose(This becomes tricky when the answers are very closely worded in verbal.)
[*] While covering the modules in eGMAT, I prepared notes for myself, which I referred to on the night before the exam.
[*] Spoke to few of my friends who has cracked GMAT previously, listened to their approaches and took in what were applicable to me(This is very crucial! What works for one may not work for the other!)
[*] Read many debriefs on this forum to keep up my energy level. If they can crack it, I can too!
Study Materials used:[*] Quant- 700 to 800 level questions in Quant from Manhattan
[*] Verbal- All the resources provided my eGMAT. I took up the Live Prep in particular in order for me to be on track. I made sure that I attended all the webinars live and not watch the recordings. This motivated me to finish the modules on time. Also, the live sessions helped me to know where I stood compared to others and also helped me solve questions in the timed environment.
[*] The forum where students discussed their doubts in eGMAT was really helpful. It often gave me a new perspective on how to approach questions.
[*]eGMAT Verbal Live Workshop
[*] 2 free online mocks followed by detailed analysis.
The Exam:[*] During the exam, I split each section into quarters and allocated time within which each quarter had to be completed.
[*] Followed the same order as that of last time
[*] I felt quant to be easier than last time. (Got a bit worried by the end of it because I felt the questions were really simple :/)
[*] Ran out of time in verbal, especially towards the end. Had to skip 2 questions in between. Attempted SC and CR using the eGMAT approach.
[*] Still worried and tensed, especially during Verbal.
What went well in this journey:[*] Got hold of a clear and concrete approach for Verbal.
[*] A good hand at the eGMAT approach in SC and CR.
[*] After the analysis of my ESR for this attempt, I realized that my SC and CR had improved a lot while I had to still catch up on my RC.
[*]More confidence.
Attempt-3
Date:26 August 2018
Score 730(Q50, V40, IR7, AWA4)
Preparation time:July 2018 to August 2018 interspersed with times of no practice at all.
What I realized from my previous attempt:[*] RC is my weak point since my comprehension ability was very poor. So I decided to concentrate more on improving my RC.
What I did differently from my previous attempt:[*] Read many articles in The Economist and tried to apply the eGMAT approach on it. I did not take notes while doing RC because I felt it to be too time consuming. But I made mental notes as I read the passage. At the end of a passage, I made a mental summary of it and wrote a one line on it.
Study Materials used:[*] The Economist
[*]Verbal- Few questions from eGMAT
[*] Quant-Few questions from Manhattan
[*]AWA- 3 essays from OG
[*]IR- eGMAT resources
What went well:[*] Unlike my state in the previous two attempts, I was more relaxed and calm
[*] Time management wasn't an issue this time. I finished the sections with 2 to 3 minutes to spare.
[*] Verbal was better this time. All the RCs went well and the topics were also relatable.
It has been a long journey filled with a lot of ups and downs. Moments of frustration, loss of hope, tendency to give up.....everything. But the journey has taught me that
if your efforts are sincere and you are determined to reach there, you will 
May you never loose the fire in you

Keep going!
Cheers