For those fortunate enough to have mobility in the shoulders, there are several yoga poses to relieve stress in this area of the body. Because the shoulders have such a wide range of movement, it's not a bad idea to incorporate as many shoulder poses as possible into a yoga sequence.
Reverse Prayer or Cowface Pose is a great starter. Then move into Extended Puppy Pose. It's a mix between Child's Pose and Downward Dog. A variation on this pose is to remain in a kneeling position with the palms under the knees. Then straighten the arms while gazing forward. It's an amazing stretch for the shoulders.
Those seeking more of a challenge should enjoy Peacock or Firefly Pose. Firefly requires more core strength, whereas Peacock is all about the arms. It's also an inversion that requires a wall for support, much like Shoulder Stand Pose. If there isn't a wall available, King Pigeon Pose is a wonderful substitute. It's a pretty intense back-bend, closely related to Bow Pose. This is another option for a more challenging pose.
Some familiar poses to include in the shoulder sequence include Triangle, Eagle, and Cat/Cow Poses. Upward Plank is an interesting alternative to inversions, and Sphinx Pose is the most gentle of the back-bends. The shoulders are very sensitive, so be careful challenging the body to these poses. The shoulders are extremely susceptible to injury.
One of the greatest benefits to a yoga practice is reaping the rewards. Stretching the shoulders and feeling the body open is the ultimate stress reliever. Finally, relaxing in Corpse Pose with the shoulders at the sides is the perfect ending to any practice.