A dancers' warm-up: stretch, plie, balance. An athlete's warm-up: bend, stretch, sprint, run, throw. A musician's warm-up: scales, breath, runs, hold long notes. A singer's warm-up: breaths, scales, tongue trills.
A storytellers warm-up: Sit until your turn comes up.
All too often, that's what it seems to be, but we should really follow the example of all the folks above. We should warm up our storytelling instrument.
Storytellers need to warm up like any other performer. They need to prepare their voice, body, arms face and mind for the process of performing (or even simply telling) a story.
Storytellers need to stretch, make their bodies soft and pliable, even if your character is supposed to be "stiff". Your instrument needs to be tuned.
Storytellers need to warm up their voices. Do mouth exercises to stretch their lips and vocal chords. Pop some "Ps, Ns, and Ms" to get crisp sounds and smooth transitions. Breath in and out.
Storytellers need to stretch their arms and legs. Check your posture and balance. Check your gestures for relevance and flow. Do your movements come from deep inside your core?
Then, when you are ready, just before you go on, take a moment; a breath. It's Showtime!