Letters of reference are a very important part of your application process, not just a hoop to jump through. Give serious thought to ensuring they are significant, supportive, and above all, relevant.
An artistic director, literary manager, or famous director of a major theatre looks great as a reference, but most people entering grad school are going to find those kinds of references difficult to obtain.
A lot of programs ask for three letters and not coincidentally, are looking for people who can speak directly to three specific things. Your talent as a performer, your ability to handle the academic rigor of a graduate level study, and your potential for success in the field. Our suggestion is to try to get references that can each speak in general about all three of those things but then be very specific about one of them.
Find someone who can speak about why they think you are a talented performer. If possible, a director, another actor, or even a playwright.
Find another someone who can speak to your academic ability, especially if that ability is not reflected in the grades on your transcript. A supportive teacher is better than the head of a department who hardly knows you.
Find someone who can speak to your passion and commitment to pursuing your dream, and if possible, mention how you have helped others to do so.
Where possible, make sure those someones are accomplished themselves so that their evaluation of you carries weight. You want references who know you well, will describe you favorably but not with faint praise, know something about the program you are applying to and your goals, and willing to take questions about you over the phone.
Lastly, remember that your reference is putting his or her reputation at risk by writing your recommendation. Don’t ask if you aren’t reasonably sure they’ll say yes. If they do say yes, don’t make them regret it.