The ball is placed at the back of the head.
Stay straight and release the ball then clap hands in front then catch the ball behind.
Move onto two claps then three. Spend one minute on this drill.
The tendency is to lean forward as you release the ball, stay straight.
World Rugby has reportedly conceded Aaron Smith's disallowed try in the World Cup final should have stood.
"It is not only useful for staff who are experienced but a valuable tool for those subject staff who have to take teams."
The variety of sessions across sports - sometimes we steal session ideas from one sport and use them with another.