music is great, its very helpful to stop sensory overload too. it doesn't really make sense bc its more audio simulation but it always helps me. (best if you stick to songs you know well, that way its predictable)

I don't do this much anymore (got pretty good at managing anxiety before it hits), but a really good exercise is to focus on one of your senses and describe everything you see, hear, feel (touch not emotion), smell, and (if applicable) taste to the last detail.

Also asking yourself why you're stressed and rationalizing it helps. Oftentimes the fear gets blown completely out of proportion, and if you can show yourself that by looking at the causes, implications, probabilities, and feasibility of the fear you can at least bring the level of anxiety down a notch or two.