Hello Mark !
The most powerful technique that I know from Touch for Health®, that can be used without previous training and outside a private session, is this : http://www.touch-sport.fr/blog/video-antistress-lse/ (sorry it's in French ! But you'll get the idea ;)
If it's not enough, or if you need help to get out of an especially stressful situation (high stakes, or recovering from a fall...), and if it's possible for you, a private Touch for Health® session is a very powerful leverage to overcome stress and anxiety in a specific situation.
More info about TFH here : http://www.touch-sport.fr/en/