Most important thing is to do your homework, introduce yourself to the acts and get to know something about the acts you are introducing. Where they are from, where else they are/have performed, etc etc.

We were introduced by the MC at a major folk festival last year with 'I don't know anything about this band, but I am sure they are going to be great' It got worse, the act following us was introduced with 'The next band are supposed to be ....... Are they here?'

John