1. Thought-stopping technique When we become anxious we begin to have negative thoughts ('I can't answer anything', 'I'm going to panic' etc). If this is happening, halt the spiralling thoughts by mentally shouting 'STOP!'. Or picture a road STOP sign, or traffic lights on red. Once you have literally stopped the thoughts, you can continue planning, or practise a relaxation technique.
2. Creating mild pain Pain effectively overrides all other thoughts and impulses. Even very mild pain - such as lightly pressing your fingernails into your palm - can block feelings of anxiety. Some people find it helpful to place an elastic band around one wrist, and lightly twang it when they are becoming anxious.
3. Use a mantra Derived from meditation, a mantra is a word or phrase which you repeat to yourself. Saying something like 'calm' or 'relax' under your breath or in your head, over and over again, can help defuse anxiety.
4. Focusing Looking out of the window, noticing the number of people with red hair, counting the number of desks in each row... all help to distract your attention from anxious thoughts and keep your mind busy. Mental games such as making words out of another word or title, using alphabetical lists etc are all good forms of distraction.
5. Bridging objects It can help to carry or wear something with positive associations with another person or place. Touching this bridging object can be comforting in its own right, then allow yourself a few minutes to think about the person or situation which makes you feel good. This can have a really calming effect.
6. Self-talk In exam anxiety or panic we often give ourselves negative messages, 'I can't do this' 'I'm going to fail' 'I'm useless'. Try to consciously replace these with positive, encouraging thoughts: 'This is just anxiety, it can't harm me', 'Relax, concentrate, it's going to be OK', 'I'm getting there, nearly over'.
Whichever of the distraction techniques has worked for you, finish by going through the refocusing exercise (it only takes 30 seconds or so, but may have a profound effect on your ability to believe in yourself and the task in hand). Different techniques work for different people, so it's worth experimenting to find the ones that are right for you. Developing techniques for managing panic can take time, so it pays to keep practising.