Let pressure sharpen execution instead of destroying precision.

Pressure does one of two things to your execution, and which one is largely a matter of preparation. If the fundamentals are practised, pressure narrows your focus and you perform better than usual. If they are not, the same pressure takes your attention and the precision goes first. The feeling is identical at the start, which is why people are surprised by how it turns out.

Rather than trying to be calmer under pressure, practise the specific actions until they need less of you. Rehearse the part you would fumble. Then let the pressure arrive and use it, since it is genuinely useful once the mechanics are secure.