Listen to music of your choice Music is therapeutic and has a soothing effect on even the most nervous speaker. Here's something you can try: create a personal playlist of music that works for you. It could be music that calms your nerves or music that perks you up.
Do voice exercises When you are nervous, your muscles tense up, including your throat. And if you don't warm up, you will sound like a strangled frog on stage. Not a beautiful sight. Voice exercises do not have to be complicated. Singing the scale works. Doing funny faces in private works too.