I find that twisting the spine helps alleviate my back pain or back tightness. I do this in one of two ways. Sitting normally in a chair, and keeping my butt in same position, I twist my upper body around, grabbing the back of the chair and trying to get my shoulders parallel to the chair back. I then repeat with a twist in the other direction.
Alternatively, sitting on the floor with my legs stretched in front of me, I bend the right leg and place my right foot flat on the floor on the left side of my left knee. Then I twist to the right, placing my left elbow on the right side of my right knee, my right hand on the floor to the right of my butt. I then repeat these steps with the opposite legs and arms.