Regardless of what happens, regardless of how you are feeling, the show must still go on. I feel performers at every level don’t keep this in mind often enough nowadays. Patrons paid to see you, to be entertained. It is your duty to do your job, perform. They don’t care if you feel like death warmed over, they don’t care if you are sick. It’s not that they are of an uncaring sort, that’s just not part of what they paid for. They paid to be entertained, your duty is to entertain.
Never apologize to an audience. You gain little by apologizing for whatever it may be, you also risk damaging what credibility you do have. Never call attention to the negatives, that only makes for a worse distraction.
Plan, plot and plan some more. But also be ready to fly by the seat of your pants.
Also make sure to have good friends on hand to hold you upright when you need it, once again keeping in mind; the show must go on.
**thanks to Tony Wear for the image