Apply to several programs. First and foremost, grades are the most significant determinant of eligibility for admission to a graduate program. As this overcrowded profession gets increasingly competitive, graduate school are tending to limit enrollments. The diminishing availability of financial aid also tends to reduce the number of students accepted by graduate programs. Except under exceptional circumstances, you should have at least a 3.0 GPA to qualify for admission.
Letters of recommendation are often extremely important.
If you qualify in both of these areas, you may then be asked to verify your artistic accomplishments, which for actors and directors may be a videotape of performances and for designers may take the form of a portfolio. Theatre historians should be able to produce a clean copy of a research paper as an indication of writing skills and scholarly apparatus. Once past this obstacle, a personal interview may be the final step. Since the MA is not a terminal degree and only a step towards the Ph. D., the competition is not fierce. If you enter the MA program and demonstrate that you are MFA material, you may be allowed to transfer in your second or third semester from one program to the other.