Guys: Stretch.
Seriously, if you can, just do it. I decided to work on my hip mobility and splits after a very long time and my god, I feel so much better. It relieved pain in my legs, back and a little bit of my desk-borne headache. If you have trouble getting started, find one particular stretch you would like to be able to do, preferably some tangible goal like a full split, and hyper focus on that.
I run a lot and was stupidly adamant against stretching because I injured myself doing it before a run like 10 years ago.
Last year I started getting pain from tight muscles at the end of my range of motion. I started stretching at the end of my runs, while my muscles are still warmed up, and it's been amazing. No more pain, no injuries, less soreness, and I feel faster.
Dick van Dyke swears by nightly stretches and he's 99 years old!
Yoga is the only reason I managed to punish my body as much as I could while running. Downside of this flexibility is I ripped another set of pants.
I NEED A ROUTINE THAT IS THE ONLY WAY