Best way to maximize your chances at merit money is to apply to schools that offer it, here's a list that I drew up from another post (but by no means is it completely accurate or comprehensive), but it should give you some idea of which schools you should spend a little more time looking at:
Washington University - some full tuition and half-tuition scholarships, maybe around 10?
Vanderbilt University - decent number of students get some merit-based money
Emory University - a handful (maybe 5) of full-tuition scholarships, no other merit money
Case Western - 15-20 scholarships ranging from $20,000 to full-tuition
UPitt - from what I hear, decent amount of people get merit based money from them
UChicago - very generous with merit based money compared to most other schools
UMich - dunno anything about how much, but they have at least some merit-based scholarships
And don't forget the schools that are already cheap to begin with, namely:
All your state schools
Mayo Clinic
Baylor
Also, different schools will have different criteria for how stats play into the decision to give money. To give you an example of one school, case western multiplies your gpa and mcat together, and if you fall above a certain threshold, then they will invite you to apply for a merit scholarship. Of course there are a few exceptions (where ppl below have been invited, and ppl above have not), but for the most part that's how it works. Then you write an essay, and they make a final decision on merit aid after that.
