1. Start Position: Stand or sit up straight with your feet shoulder-width apart. Relax your arms at your sides.

2. Reach and Hold: Extend your right arm across your body at shoulder height. Use your left hand to grasp your right elbow.

3. Gentle Pull: Gently pull your right arm towards your chest. You should feel a stretch in the shoulder and upper back.

4. Hold the Stretch: Maintain this position for about 15-30 seconds, ensuring you breathe deeply and evenly.

5. Switch Sides: Release and repeat on the left side by extending your left arm across your body and holding it with your right hand.

6. Frequency: Perform this stretch 2-3 times on each side, especially if you spend long hours sitting at a desk or engaging in activities that strain your shoulders.

This stretch not only promotes flexibility but also helps in preventing injuries and improving posture.