What helps with pre-concert tension without making you sleepy?

I am putting together some notes on pre-concert nerves for adult community singers, because the usual “just breathe” advice dont always help. One useful distinction are short stage nerves versus stress that keeps following you home after rehearsal. Sleep, regular meals and a slow warmup seems boring, but theyve helped me more than trying a new remedy right before a concert.

I found this breakdown of stress-reducing supplements useful because it covers what may help and what to skip, including some safety points: https://ask-ayurveda.com/articles/2148-stress-reducing-supplements-what-works-what-to-skip. Sharing it mainly as background not medical advice. Has anyone found a simple pre-concert routine that work without making the voice feel flat or sleepy? Late evening performances are still tricky for me, honestly