I like to do a kind of flapping thing with my hands. Sometimes I pass it off as kind of tapping a rhythm, but mostly if I want to stop, I sit on my hands. Then I get this tendancy to rock backwards and forwards or to hum. So to deal with that I make the rocking motion really small so it's not very noticable and I concentrate on following my breathing - not changing it or anything, just watching what it does. I do these things because the rhythm helps to calm me down. If I can get myself to the point where I'm focusing on breathing then I feel like I've won becuase breathing is always allowed and it's a rhythm too (except in a chest xray when they tell you to hold you breath for a few seconds.)
Another thing I do sometimes if I'm stressed is I put earphones in and hold my phone or mp3 player in view so people can see it - then if people see me tapping a rhythm or rocking, they just think I'm moving to the music (I hope). The secret is though I don't like listening to music - I actually listen to the Harry Potter stories read by Stephen Fry - which also calm me down.
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"That's no moon - it's a spacestation."
Diagnosed with Autism Spectrum Disorder (ICD10)