I need to stretch out my hamstrings and lower back, a lot. This $9 PT strap helps.
I ceased being super active and spent much of the last year or so in "avoid backpain" mode. Slowly, I lost more of my range of motion. When I did go and do supremely dumb things like ride a motorcycle 600 miles in 2 days, or nearly strand a VW bus in a not-so-dry Mexican lake bed, I hurt real, real bad for a real long time.
I decided to start doing something about it! Fancy that. Stretching is job one. Refusing to use a pants belt, I got a strap just like the one I used in physical therapy. It helps. Having a dedicated stretching tool right where I'll use it is a good idea in my book.
I will not recommend exercises! I use some my PT/pilates folks gave me a few years ago (before I stopped going and slowly began down the road to atrophy,) as I think you need to find what works for you and won't make things WORSE. Google and YouTube offer a ton of help, if you wanna go it alone.
Next up is a spinning bike for lower-impact-on-the-back cardio that I enjoy.
Therapist's Choice Stretch Strap via Amazon