Follow through, finger spin
When a follow through is performed well it is a sign that the bowler is getting though the action and putting revolutions and spin on the ball.
Back leg drive.
A strong back leg drive helps the bowler get up and over the front leg which is important as it allows the bowler to use their body and complete the action. The feeling should be driving up and over the front leg.
180 degree rotation
In combination with driving the back leg through the action, ideally the bowler rotates 180 degrees. This will allow the body and major muscle groups to contribute to putting energy and spin on the ball. When rotating it is important that the bowler drives up and over the front leg rather than rotating on the spot.
A good tip is to direct the bowling arm shoulder and back hip to the target on completion of the action before transitioning into a front on fielding position.
The bowling arm should feel as though it is long through the delivery heading towards the target before finishing on the same plane that the front arm travels. This will assist with accuracy. Keep the arms tight to body.
The bowling arm finishes past the front hip and the movement needs to be energetic and fast. This energy correlates to more revolutions on the ball.
The front arm tucks into the hips before extending which allows the bowler to finish the action.
A very misunderstood part of the bowling action for junior cricketers is that there is a tendency to pull up short after the ball is released. The energy required in the action should force the bowler to follow through down the wicket 3-4 metres. This follow through needs to be towards the target rather than falling away.