Strong letters of recommendation. Schools will also look at what you did outside of school. Work experience is preferred and many MBA students who attend top programs do not apply right after they receive their degrees. Experience is an important asset. Good luck!

develop strong public speaking ability, networking skills, and get to know some grads from the program/s you want to pursue. good luck!
Oh, yse, I almost forgot- work on your golf game. That is one of the classical networking activities for MBA’s.