The club over shoulder rotation stretch is an effective exercise to improve flexibility and rotational mobility in the shoulders and upper back. Here are the steps to perform the stretch:

1. Stand in a comfortable, balanced position with your feet shoulder-width apart.
2. Hold a golf club horizontally behind your back, resting it on your shoulders.
3. Grasp the club with one hand over your shoulder and the other hand under your opposite shoulder, creating a crossed position.
4. Maintain a relaxed grip on the club and keep your elbows pointing out to the sides.
5. Slowly rotate your upper body to one side, allowing the club to move with your shoulders.
6. Keep your lower body stable and avoid leaning or twisting at the hips.
7. Hold the stretch for a few seconds, feeling the gentle stretch in your shoulders and upper back.
8. Return to the starting position and repeat the stretch on the other side, crossing your hands in the opposite direction.
9. Perform several repetitions on each side, gradually increasing the range of motion as you feel more comfortable.
10. Breathe deeply and relax throughout the stretch, avoiding any sudden or jerky movements.

The club over shoulder rotation stretch helps to loosen up the muscles and joints involved in the golf swing, promoting a more fluid and unrestricted movement. It can be done as part of a warm-up routine before a round of golf or as a standalone stretching exercise. Remember to listen to your body and not push beyond your comfortable range of motion. If you experience any pain or discomfort, stop the stretch and consult with a healthcare professional.

Here's another great little stretching exercise that can not only help with your flexibility, but can also help with the technical aspects of your golf swing as well if done correctly.

So it's going to work on the rotational motion in your shoulders. But if you can combine this with a mirror or reflective window that you can see yourself in, or even a shadow out in the golf course, it can help improve your technique as well.

When say the golf club, place the handle over your front shoulder, cross your arms over your chest, stand up really nice and tall with your head up. Now if you can, look at yourself in the window or the mirror or look down at the shadow on the floor. And then work on making a nice rotational movement. If you can't take the golf club to 90 degrees, not necessarily beyond 90 but as close to 90 as you can, try and restrict your hip on your knee action.

If a golfer dose not struggle with flexibility, they'll find it that easy just to lift that front heel and turn all the way around. That clearly — that is the action we want in a golf swing. So if in a good setup, turn around as far as you can restricting your knee and your hip action to a certain degree and work on creating a tension, sort of coil in your body. So the shoulders turn, the knees and the hips resist there from creating some tension. And then you might follow through, once I've turn this way, might follow through round to a big finish.

Now, in your finish, your hip and your foot can lift up because we don’t need to create tension in that phase of the swing. In fact, that phase of the swing is all about releasing the tension. So the body weight drive to the front foot, the heel and the hip will come around will end up facing forward. So, from a nice setup placing forwards here, turning back looking at my head and then turning through and facing through the targets.

The other area you can concentrate on there is watching what your head does laterally; making sure that the head doesn’t slide away to the right hand side and slide away back again. It's a nice centered turn one way and then a turn through.

So it helps with your flexibility. But also done correctly, it can improve the attributes of your golf swing as well.