https://tradingkse.wordpress.com/2010/11/06/trading-psychology-how-to-think-like-a-trader/ 

Trading can be an extremely emotional experience for many people. Especially those who are trading for an income. As they feel pressure to make a certain amount of money in a certain timeframe, they risk emotional and overtrading. There are many ways to avoid this though, first, start trading for fun. Trade for the sake of learning a skill not as a means of survival and it will be much easier to trade level-headed. Second, never trade with money that you can’t afford to lose because you will lose. Do not expect to become constantly profitable for 9 months to a year. Treat a hobby as it should be treated for fun, enjoy what you do not tie stress into it.  

With that being said we know it is unavoidable to trade without stress, so how do you alleviate it, as you would any other stress. #1 Rest, if you were up all night with a family emergency, don’t trade the next day. #2 Refuel although trading is not physical a good breakfast, and being awake and alert is critical. No one is productive when they are hangry.  #3 PREPARE The night before and the day off you should be scanning your markets and tools and have what you are trading. You should never be frantically flipping through charts once the market is open. #4 Stick to your plan. Whatever you prepare to trade is what you should trade. Do Not second guess or stray from your initial plan. #5 Recoup Find your release, exercise daily. Every day you should have a physical release and de-stress of your body. Most important Exercise and meditation.