First of all, get the right material, I mean books:
1. MGMAT guides
are must have books, especially if the math is not your strongest area. Study 1 chapter a day at leas, roughly
in 2 months, I am sure you will be able to go over all 8 books + do OG tests.
That should lift your score at least 50-60 points.
2. If you are shooting even higher, I would recommend GMAT club tests
, and GMAT Club Diagnostic Test. They are perfect tests for those who are shooting above 700.
Never give up,,,