[jancsika]

If you've never done it before, consider drilling every single aspect of the performance.

For example-- in a performance, you usually walk to the instrument, bow, sit down, adjust the bench, pause, consider the tempo... all to play the first few notes that establish the tempo of the piece.

So you would drill that entire entrance, as well as drilling from a sitting position and establishing the tempo.

What you'll probably find is that the variance in speed among these drills is well beyond what you desire for your performance. And the more you drill, the more control you have over the established tempo, which is probably the most important moment to not make a mistake. :)

This approach doesn't "solve" nerves. But it can slowly decouple them from the performance. E.g., you start freaking out because you never noticed how "weird" your thumbs look in this passage; nevertheless, muscle memory established a nice, solid tempo for your freakout instead of one thats 1.5x too fast... :)

[KineticLensman]

Yes. I've used this for public speaking. Also for parachuting, where I finally got a clean jump (back in solo static-line days) by working through in my mind all of the distractions: stall alarm sounding, jump-master shouting instructions, clambering into the door (seated position in a Cessna), smell of exhaust fumes, slipstream.