Drawing on a balloon presents its own set of dangers. An accidental bump by someone walking by or an excited, grabby kid can destroy the princess’ face.
To guard against such dangers, always stabilize your hand on the balloon. I rest the pinkie side of my hand on a balloon when I’m drawing. Others only rest the pinkie finger. Either way, if your arm or the balloon is bumped or grabbed, the balloon and your drawing hand move in unison.