Take a look at this impressive automatic shoulder rig capable of independently tracking the Upper Arm and responding accordingly, created using Blender by 3D Artist and Character Rigger known only as rimsckei on Reddit.
According to the creator, the project's initial goal was to achieve the most accurate shoulder deformation possible without using Shape Keys, adding corrective shapes only as a final refinement if necessary. The lifting motion is controlled by a single bone – Wrist_bone in IK mode or UpperArm_Rotation in FK mode – which, according to the artist, greatly speeds up the animation process.
For comparison, here's an earlier version of rimsckei's shoulder rig:
