Reinvent the Wheel
Specifically working on shoulder flexion, spinal extension and hip extension, in isolation first before working our way towards integration. You'll be best served by using a few bolsters (or a stack of blankets), a couple of blocks and a strap or belt. Not too long of a practice but still builds ...
Explore lots of types of shoulder movement in familiar postures and explore how eagle pose can build towards stronger arm balance bases. We journey from thoracic mobility, cactus bridge (yep) to Eagle and dolphin variations.
Upper Body Detour Flow
Detour flow, with emphasis on upper back and shoulders. Have a blanket or bolster on hand as well as one block.