My spine mobility isn't terrible, but it could be a lot better. I love Cat Cow because it's another gentle exercise to warm the spine up before exercise, but it's also great for overall spinal mobility. I tend to perform 10 reps in each direction, but I recommend doing what feels best for you.
Begin on your hands and knees so your back is flat and your abs engaged. As you inhale, let your belly soften, arch your back, and lift your head and tailbone. This part of the stretch is called Cow.
With an exhale, round your spine up to the ceiling, pull your abs toward your spine, and simultaneously tuck your tailbone in and draw your chin toward your chest. This part is known as Cat.
For a minute or so, continue flowing back and forth from Cat to Cow, breathing deeply so as not to rush each movement.