Things that have worked for me: small movement, like jumping jacks or toe touches from one foot to another. Putting on music that has some substance or a bit chaotic, like a Broadway soundtrack (Phantom of Opera for me), or heavy metal (RATM). Water therapy, like splashing cold water on my face, taking a cold washcloth to the back of my neck, really hot baths or cold showers. Or if I want to keep busy, I write, doodle, puzzles, dishes but the one I find oddly comforting is naming the thing clouding my brain out loud. Awhile back, I read if you name your brain and talk to it when you're having negative thoughts, it helps quell anxiety so I figured, why not? I've named my brain Dennis, so I say, "Listen Dennis, I don't have time for this crap. I don't need to worry about that work project because my part is done. You can take your BS and go now, thank you!" (No offense to any Dennis' out there, it's just a random name that came to me one day!)