Magic Choral Trick #205 More Spinning
You may not get 100% compliance immediately from the people who are nervous about looking silly – but its worth some persistence for the effect this has on tuning.
More spinning: Index fingers point at the temples, then rotate fingers, circling the temple area – moving up and forward, then down and back, then around again and again. Seems to work best if both fingers are moving in unison – like the wheels of a car.
Do this while you’re singing a sustained note that’s been sitting a bit low, and it should bring it up to pitch.