Stand in a neutral position, with both arms by the side. You may choose to either:
a) squeeze a tennis ball (or similar balls) in one hand
b) hold a light weight plate or dumbbell (~1kg) in one hand
Start with the loaded arm by the side, with palm facing backwards. You will then rotate that loaded arm, thinking about making big circles with the hand, by first drawing the arm across the chest then upwards (palm will be facing forwards at the top position) and back down to the start position, and repeat in the opposite direction. Repeat this movement 3 circles per direction per arm. All movements should be in a controlled manner, with deep breathing.