For little beginners:
1. Children love the game Simon says - they do only activities with Simon says, but they don´t have to do activities without this.
For exemple: Simon says touch your mouth. Simon says touch your ears. Touch your nose ...
2. Children take a baloon, we say body parts and they a ball pit with this part, e.g. with leg, knee, shoulder,...
For an elementary group:
We say more difficult commands such as put your right hand on your left shoulder, put your left hand on your right knee, put your right foot behind your neck....