It really depends what your back pain is from. If you've thrown out your back you might need physical therapy or an adjustment before it starts feeling better. Ice definitely helps if it's muscular. I've been on the mend myself this last week from lifting something poorly. https://youtu.be/K8SD47gLB-I here's the yoga video I always go back to when I do this to myself, usually about once a year.
For me it's yoga. Doesn't have to be long or even a structured session, just taking the time to stop and stretch and reconnect with myself and my body does wonders.