It’s not necessary to learn a variety of grips to play badminton. Badminton England coach Mike Hopley recommends on his website learning the basic grip for both the forehand and backhand strokes. Players can always evolve to other specialized grips as technique and form improve. With the basic grip, the positioning of your thumb varies slightly between the forehand and backhand stroke. The thumb is not as involved in the forehand stroke; the forward push of the racket is done with the index finger. On the backhand, the positioning of the thumb keeps the racket stable and helps you hit with power. The key to a good grip is to keep it relaxed.
Hold the shaft of the racket with your non-dominant hand. Position the racket so that the strings are perpendicular to the floor, the head is pointing away from you and the handle is pointing toward you.
Extend your dominant hand and grasp the handle as if you are shaking someone's hand. The edge of the handle should be aligned with the heel of your hand. Wrap your fingers comfortably around the handle.
Examine the position of your fingers and thumb. Your fingers should be spread along the handle with space between the fingers. Avoid bunching your fingers together as if you are making a fist. There should be a wider gap between your index and middle finger. This is referred to as a trigger finger position.
Position your hand so that your thumb and index finger form a "V" shape on the top edge of the handle. Your index finger should be higher up on the handle than your thumb. While holding your hand in this position, slowly move your hand counterclockwise so the "V" is now on the next bevel. This hand position allows you to hit both forehand and backhand strokes without changing grips.
Curl your thumb around the handle when hitting forehands. Extend and place your thumb straight with the pad of your thumb on the flat side of the handle to hit backhands.
Test to see if you have a relaxed grip. Coach Hopley suggests that a relaxed grip allows your forearm muscles to work more effectively. Grip your racket and ask a friend to grasp the head and take the racket out of your hand. If there is resistance, you are holding the racket too tightly. The tightening of your hand should only take place just before impact of the shuttle.