things I've found helpful:
hot Epson salts bath -- a hot bath is relaxing by itself, even without the Epson salts. but Epson Salts are a good source of magnesium which most folk are deficient on. My pet theory on why floating in a float tank is supposedly so relaxing it the water is loaded with Epson salts. If you are deficient and spend an hour a week for several weeks soaking in that solution, you will indeed feel much better.
Meditation -- I favor a basic follow the breath, but anything that gets you in the moment and gets your mind off the source(s) of stress will only help. I have been known to combine this with the Epson salts bath, or with a shower to "wash the day/week/etc off" -- just standing in the spray counting deep breaths. If your mind wanders, don't assume the meditation isn't working. Just label it "thinking" and go back to the meditation. Another strategy is to just observe the thoughts and watch them drift away.
Music -- I routinely use music designed to stimulate delta waves to sleep, and beta or above to stay awake. for simple relaxation go for alpha. Theta is good for meditation.
Valerian root is helps calm. I take a bunch of it every night, but sometimes take extra when stressed.
I'm still exploring stimming -- I've always been into rocking chairs, swings, and bouncing my leg, even though I never before made the connection between the activity and my stress level, but I'm rediscovering spinning. It seems to calm me better than just about anything.