Here are some resources I've found helpful. Feel free to chat with me about any of these.
"How to Make Performance Anxiety an Asset Instead of a Liability," Noa Kageyama
Synopsis: Use centering to shift from left-brain thinking to right-brain thinking. This performance psychologist and Juilliard alumnus and faculty member provides a 7-step centering process.
"Inner Game of Tennis," Tim Gallwey
Synopsis: A best-seller book used by many professional performers to help them get out of their own way so that their bodies and minds can deliver the performance they've been training so hard to deliver.
Walk through a game plan -- learn the mental game that professional sports players play, Joyce DiDonato
Gist: In an interview, DiDonato muses about how in high-level sports, players learn how to walk through the game plan for a big game day -- the blow-by-blow of how they'll go out there, do what they have planned play-by-play, and how they can have alternative plans as well. Yet in music school, we don't teach our students how to do this. She proposes that for high-stakes performances, we walk through a game plan pre-show, and we mentally prepare ourselves in the same way high-performance athletes have learnt to do.
Application: Center ourselves and walk ourselves through what the plan is for the show -- actually verbalize our step by step game plan. For example: when I get to the theater, I'm going to sign in, do warm-ups, get in my wig-prep, then go to fight call, then get dressed, and then describe in detail (step by step) what I'm going to do in the scenes, and how I expect my body to behave, and what I'll do -- you can work in centering actions that are in Kageyama's article above. This preparation can go a ways in calming and focusing your mind for what you need to do.
Do it for someone else, Kristen Ruiz
Gist: My voice pedagogy professor at NYU shared this very helpful thought: when I'm really nervous, I should think about doing the show for someone in the audience who really needs it -- focus on why they may particularly need what I have to sing/say, and make it about them, so that it's less about me. We have such capacity to do for others what we may not be able to do for ourselves.
Rewiring Stage Fright A Neuroscience and Art Conversation, with Fay Simpson and Marcia Lesser
Synopsis: Understanding what's happening in your body during stage fright, and then training yourself to mobilize rather than lock down. Useful practical 6-step application at the end of the interview.
TED Talk by Kelly McGonigal on how to make stress your friend, as well as her book, "The Upside of Stress"
Synopsis: Stress is bad for you only if you believe that to be the case. See stress as a positive (your body helping you rise to the challenge) and reach out to others (be social) as an (oxytocin-related) intervention for reducing stress. When you change your mind about stress, you can change your body's response to stress.
"Managing performance anxiety and improving mental skills in conservatoire students through performance psychology training: a pilot study" by Margaret Osborne, Don Greene, and Dom Immel
Synopsis: Your heart rate, breathing and physical tensions will change when you're anxious -- whether these have a detrimental effect on your performance or not depends on how you interpret these symptoms. Performance psychology coaching intervention can help to reduce anxiety.