Trade planning should put you in higher percentage trades and keep you out of bad trades. The key is to plan the trade in advance so you can implement your technical and fundamental analysis.
Sun Tzu said in the Art of War:
“Planning is a great matter to a general [trader]; it is the ground of death and of life; it is the way of survival and of destruction, and must be examined.... Before doing battle, one calculates and will win, because many calculations were made.”
Planning your strategy so you can implement your cold, hard, logical analysis will help you manage your emotions. Management of your emotions, in turn, removes a lot of the stress of trading. Perhaps, because you have a clear head and solid analysis, your trading has a better chance of surviving and thriving.
With a strategy in place, now you need to turn your focus to your tactical implementation of your strategy.