Many of these are yoga positions. Work to achieve them slowly. ~ Muscle assisted shoulder stretches: tricep stretch, one arm over the head, both arms over the head, cow face yoga position, grab an elbow be.
A great article on activating the Serratus Posterior Inferior to provide overall core support. Queuing the lower rib-cage down enabling an anchor for ease of arm movement as well as protection of the solar plexus.