How to improve your wrist action

To improve your wrist action is to focus on using only wrist action to strike the shuttle during your training drills.
Be it punching lob, drop shots, smash, defense, push, drive or flip. As long as EVERY strike you make you must use your mental to feel that wrist action.

This will reduce your lower arm movement and as a result your supinator and pronator will have to work more.
Good results will be felt at the end of the training, when you feel that there is a burning sensation at your supinator and pronator. Lactic acid is been built up and you may be feeling fatigue after training.

Using weights doing wrist curl is only creating a resistance to be felt. The next step is to convert that resistance into actual application during training drills.

Enjoy your training especially when you feel that sensation created by your targeted objective of the day.