Acknowledge interference. When something goes wrong and it's not your fault, be cool enough to acknowledge it. Continuing robotically with your message highlights your desire to deliver and get off the stage. Be cool with stuff going wrong, and bring it out into the open.
Here are some examples:
1. If someone walks across your stage, you may have a one-liner like, "Don't worry, it's just a stage you're going through."
2. Playfully pose for the photographer as they try to catch you in an action shot.
3. If you stuff up a word, laugh and say something like "Ha! There goes my brain running faster than my mouth, but that's nice - it's usually the other way around."
4. If the AV technician needs to adjust your wireless microphone mid-flight, you may want to say something like, "Look, I don't have time to dance with you."
Stay cool. It's not about perfection; it's live. Make it real.