How can I effectively stretch my pectoralis minor muscle to improve my posture and reduce shoulder tightness?

To effectively stretch your pectoralis minor muscle for better posture and reduced shoulder tightness, try doing a doorway stretch. Stand in a doorway, place your hands on the door frame at shoulder height, and step forward with one foot. Lean your body forward until you feel a stretch in your chest and hold for 30 seconds. Repeat on the other side. This stretch can help lengthen the pectoralis minor muscle and improve your posture.