during the day take a few and lift up your arms to shoulder height, bend your elbows, and do pulses toward your back as if squeezing your upper back together.
concentrate on stretching your chest at the same time and of course holding your stomach in tight.
take deep cleansing breaths as you move. then at the end, straighten your arms out shoulder height in front of you and clasp your hands together, bend your head down, round out your shoulders and proceed to pull your clasped hands away from your body to stretch the shoulder area where you have just done the work- breathe.
finish with one more graceful stretch backward with your arms.