The Japanese samurai warriors before going into battle used to remind themselves about the inevitability of loss. They were said to die before going into battle. Once they had mentally died and accepted death as a very real possibility it freed them from trying to control the outcome of their battle. It also helped them transcend and eliminate their fear.
Today we all have stressful situations in our everyday lives. It could be standing up to give a presentation, going to a networking event, an interview or having a difficult conversation. What is it that makes these situations stressful? If you look closely you will see it is not the situation itself that causes stress. It is our concern over the outcome and our attempts to control the situation.
In practice letting go of the outcome means you prepare for the task ahead of you as much as possible. Then when your preparation is over, acknowledge that you have prepared as much as you can and that things may still not turn out as you desire. This is accepting the very real possibility of failure. This is different than negative thinking. Negative thinking is usually habitual and repetitive in nature. Acknowledging the possibility of failure brings you face to face with reality so you can better deal with what is in front of you.
When you die before going into battle as the Samurai did it ends your need for constant manipulation and control of outside circumstances. The struggle ends. Our whole approach to the situation changes. We are just in the moment handling whatever arises. Not stressed. Not anxious. Just moving through the situation spinning, dancing, succeeding and failing.