I struggle with this on and off and I would really like to find a way to deal with it. I go through stages with it and am starting to get some bad episodes. So far things that have helped me are to make sure I eat and sleep well and to get regular exercise. I also use distraction (like mucking about on line!) and make sure I stay on top of my work etc. Sometimes I feel frustrated though because even though I know in my head that my level of anxiety is a)out of proportion to what is actually happening in my life and b) not actually helping anyway I don't seem able to switch it off.
If you have managed to beat anxiety I would love to hear what worked for you.