Preparing students to perform starts long before the actual show. Make it a point to have your students perform for one another, and take the opportunity to teach the class how to be a supportive audience. If students practice both being a performer and an audience member in a safe, nonjudgmental environment, they will associate comfortable feelings with performing. You build a trust in them and thus reduce anxiety for the long term.
Be sure performance pressure isn’t coming from you. I know I’m guilty of it. It’s easy to get lost in the stress of putting on a show. If that’s what we model, then that’s what the students learn. We should remember that the entire experience the student has will shape their feelings about dance, perhaps for a lifetime. I remind myself my goal is to leave the student loving dance. When I have a student resistant to performing, I tell myself that the process is my priority. I ask myself, “Did they participate in everything else? Was that a positive experience?” If so, then that’s enough for me.