I have found a couple of exercises very useful for acute tweaks and chronic rotator cuff injuries. The sleeper stretch is pretty good, you'll be able to find images or videos explaining it. Another exercise I really rate is lying on your left side with the upper right arm held against your side with the elbow at a right angle. Then take a weight in the right hand, can of beans is enough to start with, and twist your upper arm to lift the weight off the floor, always keeping your elbow pinned against your side. You should do as many reps as you can, probably around 30, then switch sides. If you can do way more than that increase the weight. It shouldn't be painful but I think it specifically targets rotator cuff muscles which should feel very tired (almost like powering out). You can do a very similar exercise standing with a theraband but a i have found the lying version much more effective.
In terms of prevention and reducing pinching i found found any exercises that move the resting position of the shoulder down and back to be very useful. Such as rhomboid strengthening exercises and pectoral stretches.
