how to improve Verbal?

hi All,

I am thinking to retake GMAT. Please find below my scores in the prep tests and real test in previous attempt.

MGMAT CAT1 - 620( V-29, Q-47) ( Jan 25, 2012)
(Correct ques in Verbal SC -8/15, RC 4/12, CR 7/14)
MGMAT CAT2 - 620( V-32, Q-43) ( Feb 12, 2012)
(Correct ques in Verbal SC -7/15, RC 6/12, CR 7/14)
GMATprepv1(1) -640 ( V-26, Q50) (Feb 26, 2012)
(Correct ques in Verbal SC -11/15, RC 7/12, CR 8/14)
KNEWTON - 650 ( V-33, Q-46) (Mar 18, 2012)
(Correct ques in Verbal SC -11/15, RC 4/13, CR 10/14)
GMATprepv1(2) -720( V-38, Q-50) (Mar 25, 2012)
(Correct ques in Verbal SC -11/16, RC 12/14, CR 8/11)
MGMAT CAT3 - 730( V-40, Q-49) (April 1, 2012) ( Verbal score is inflated as I encountered 2 already attempted RCs)
(Correct ques in Verbal SC -9/15, RC 10/12, CR 8/14)
MGMAT CAT4 - 690( V-34, Q-51) (April 8, 2012)
MGMAT CAT5 - 670( V-33, Q-49) (April 11, 2012)
GMATprepv2 - 700(V-33, Q-50) (April 15, 2012)

GMAT - 690 (V-32, Q-50) On 17th April 2012.

I am targeting 750 this time. I know I need to drastically improve my verbal to make that happen. Any suggestion is welcome.

Thanks,
Manuag