How do you calm down?

I had a thought... Can I use this platform to ask for recommendations? Let's try this out. :) (I'd pay for this service.)

Recommendation wanted: What's your best way to calm down?

You might know the state: tense muscles, racing thoughts, anxious. Your nervous system is on fire. What's your most helpful method to get back to calmness and inner peace? The more specific you can be, the better. For example, it could be a specific video, a specific music song, a specific meditation exercise, a specific sequence of steps.