Nothing beyond what is commonly reiterated on these forums: a strong writing sample (personally, I suggest something you have published in a good journal, if possible), careful fit with program, contact with POIs, a well-written and imaginative personal statement, etc.
Conquistadora,
What schools did you apply to? And, if you don't mind me inquiring, why do you think you did not receive acceptances? What changes have you made to your application?