This stretch is super great for shoulder flexibility, and helps undo the tightness we create in our shoulders when we hunch over a computer.
Raise your arms from your sides, parallel to the floor. Bring your arms toward each other in front of you, hooking your left elbow under your right so the backs of your hands are touching. If you can, hook one hand over the other so your palms are touching. Make sure your shoulders aren’t riding up, and, without releasing your hands, press your elbows upward and your hands away from you.
Here is a video that makes this explanation much more clear.
Try this for 30 seconds on each side when you need a quick break and your shoulders will thank you!