This will sound silly, but...
My first trade: I was clueless and opened an Etrade account. My first trade was long DCLK. It was a marketable limit order, the limit was set to about two points above what was the current price. As I said, I was clueless, I thought this would be just like a market order with added safety. E*trade waited over half an hour to fill me just so they could screw me for 1/2 a point (filled me right when the stock turned.) This was already (I believe) illegal then, as there were new rules out concerning the handling of limit orders. I lost about half a point on the trade, sold, then sold short the same stock, this time using a market order. I got so nervous watching the stock that I eventually turned the monitor off, took a shower, then watched some tv. Two hours later I covered for a 2 point gain.
For the first few weeks anxiety was always a major problem for me, maybe that's just my nature, or maybe I was risking too much (always positions in a single stock, well over 100% of equity.) Also, this was supposed to be my new profession, borrowed money from parents, etc., really didn't want to screw up.
Two things helped me get over that problem, one - I simply got used to trading, two - I no longer make any decisions about a trade while trading, not if they aren't already a part of my system or strategy. In other words, I don't use my 'gut feeling', I don't rely on impulses that I can't verbalize and that can't become part of my system, I no longer care about any individual trade (or at least I try not to care, and am starting to get pretty good at it) I care only about perfecting my strategy by carefully and over time adjusting it to the changing conditions in the market. As someone put it, 'I plan my trade, and trade my plan.'
Faced with a situation that is not covered by my strategy, I simply go flat, or look for another opportunity.
voodoo