I'm all for making the most of my time, so I like to pair stretching with breathing to create mindful movement practices that relax my tense body and busy brain at the same time.
My favorite is doing head rolls that are synced to the in and out breath. I learned this one in a yoga class many, many years ago, and it's has been a tried and true relaxation and mental reset technique since then.
It's a bit difficult to explain how to do it, so I'd rather show you. Just check out the video below.
A note of caution, please be gentle or don't do this exercise if you have neck injuries. Listen to your body, go slow, and stop if you feel pain.