This is a great hip mobility drill that works on both hips at the same time.
Sit down on the ground and set up one leg in front of you, creating a 90-degree angle from your hip to your knee to your foot. Create the same 90-degree angle with your back leg.
Then, sit up as tall as you can and put your hands at your sides. Start shifting your weight over your lead leg (the leg that you put in front). The more you lean forward, the greater the stretch will be. You can help yourself stretch by walking your hands forward as you lean. Remember to keep your back straight as you lean forward.
Next, shift your weight back so that your torso is upright and vertical and begin to raise your back knee up toward the ceiling. This is where you’ll feel a deep stretch. You can repeat this several times.
Finally, drive your lead leg into the ground as you bring your foot up towards the ceiling. If that is difficult to perform, try placing your arms behind you and drive your back pocket towards your front knee.
It’s all in the hips. In order to have an efficient golf swing you need to have both internal rotation (rotating into your hip) and external rotation (rotating out of your hip).