If the pressure is getting to you, whistle. In a barely audible way. It's the best way I know of to let go of tension. Music gets your mind off the situation, and the act of whistling melts the tension out of your body. ↗
Your purpose is to make your audience see what you saw, hear what you heard, feel what you felt. Relevant detail, couched in concrete, colorful language, is the best way to recreate the incident as it happened and to picture it for the audience. ↗
The best way to study is to go to the Cecchetti method for about a year and draw onto all the highest points and then put that into the general method. ↗