This exercise can be played in groups (3-4 people ideally) or as an audience exercise with one improviser on stage and everyone else participating from the audience.
One improviser stands at neutral in the middle of the playing space and asks
What do I do first?
Any of the watching improvisers can answer.
You rub your hands together.
The improviser must rub their hands together. They then ask
What do I do next?
The exercise continues and a story is created. Every time the performer needs more input they ask again
What do I do next?
The performer gets to control how they fulfil the action request.
There is actually a back and forth between the performer and the narrators. Each can give gifts to the other - the way actions are performed are just as instructive as the words used. Both parties must be open to these gifts of pace, tone and performance.
Narrators can only give the performer physical actions to do, they can't narrate internal monologue or feelings - You hold your face in your hands NOT You feel sad.
A very advanced version of this game allows you to do nothing but describe physical actions. So you can't even say You get punched in the face, you would have to say Your head snaps back suddenly and you rub your nose.
If the performer wants to end the scene, they can say
What do I do last?