GMAT Strategy

Hi all,

This is my first post here. Took the GMAT for the first time yesterday and scored 640 (41 Math/37 Verbal. Needless to say I'm a bit disappointed as I need a higher score for the competitive programs I'm applying to. I'm retaking the exam December 22 and was wondering if you guys could provide some advice as to what my best strategy should be? I already took the Kaplan 'Advanced Course'. Would you guys suggest getting a private tutor, if so who are the best, or are there some other good materials that will benefit me in this time crunch? Thanks in advance.