Within a drama classroom and even within a classroom of any discipline I think that some of the techniques of differentiate instruction that really drew me in were:
flexible grouping--maybe placing students in different ability groups and then moving them depending on the rate at which they are going which leads to...

on-going assessment--although formal assessment is not a huge excitement for me, I like the idea of informally assessing along the way (exit cards, small assignments, short presentations etc.) just to make sure my lessons are applicable/current etc. and students are okay where they are at.

scaffolding/meeting the student where they're at--I like the idea of meeting a student where they're ability is currently at and then building them up. Pushing them a little bit further every assignment or every question. I also think that it is important that positive reinforcement is key. Like in the movie we watched where the teacher read out loud the story with "a writer's voice". That student will have that much more confidence in his/her ability.

I think that the first strategy I would try to implement within my class would be assessment. Without that, i know nothing about my kids' where about's. Assessment first, than scaffolding and as I get more confident, and comfortable I would go out on a limb to group.....flexibly.