Here's a few feel good movements (so much better than calling them exercises/stretches) that I've used when I've overdone it at something I enjoyed way too much:
1 -- Lift one arm up to shoulder level and cross it over your chest. Use the other hand to grasp it at the elbow and gently pull it closer to your body. Hold for several seconds, then repeat on the other side.
2 -- Go stand in the corner! I mean it. Then put your hands up at shoulder level against the two walls, fingers of each hand pointing toward the other hand (this raises your elbows up and rotates the shoulder joint) and do a few "push ups" from the wall. You will have to figure out how far away from the corner to stand so you can comfortably do these pushaways.
3 -- Get a plastic jug with a handle that's comfortable to hold and put some water into it (I use gallon milk jugs). Stand near a counter or a wall to support yourself. Lean forward and let the hand holding the jug dangle, drawing circles in the air with it.