@Randy George I like the "pendulum" stretch for improving passive ROM. You can also do it by doing a short lunge with your good side leg forward and resting that side elbow on your thigh, with the injured arm hanging down. The weight should definitely by light and held with a loose grip. I like handwriting the alphabet as large as possible while staying pain-free. The motion should be through subtle body motion and not the shoulder muscles. For active range of motion I like doing figure eights with the injured arm. Starting standing up straight with the arm in neutral position and working through all of the shoulder ranges, make the figure eights as large as possible keeping the motion pain-free. The figure eights can be done in any plain (i.e. sagittal or coronal in the neutral position) and the direction can be changed up. Also wall-walking by facing a wall or perpendicular to the wall using your fingers to walk up the wall (passive for the shoulder muscles) approaching the pain but not going into it (that's the rule in general).