In conclusion, we can say that one can bring 5.0-6.0 on AWA section of the GRE, if He/She includes and demonstrates the fundamental grammatical skills. I want to retake GRE and expect 4.5-5.0 this time. i think the Engineering schools bother less about writing section. They do care about Quants section. Moreover, AWA section is given weight for fellowship consideration.
I've practiced enough and followed the Kaplan template of Issue and Argument Writing...What I want is GRE score of 310+. I hope I shall get the desired score.