Sit hips back toward heels while reaching hands and arms forward.
Alternate rounding and arching back to stretch and lengthen spine. Actual cat optional. ;)
On your back, hug both knees to your chest, stretching your low back. Or alternate one knee at a time.
Hug a knee to your chest, then pull it across your body. Reach your opposite arm out to the side.
Lie on your stomach and press up onto your forearms. For added stretch, try to straighten your arms and you lift your chest higher.
Press the small of your back down into the floor and pull your pubic bone toward your ribs.
Lying on your back, cross ankle over opposite knee and hug toward chest, stretching piriformis and back.
option 1
This is the same move, but can be done while sitting in a chair. Only lean as far as you can without discomfort.
option 2