But after 30 years in corporate awards, I can count on two fingers - how appropriate - those "stars" who have been difficult to work with.
It's my experience that if you treat them right, they will deliver. So, if you've never had the pleasure of a celebrity before, here's the beginner's guide.
Having been thoroughly briefed (RSVP, April) your star arrives for rehearsal.
Do not let them talk you into avoiding a rehearsal - it's reasonable to insist that they "stagger" through a full technical run. Remember, you won't get their full delivery at this point; that's always kept in reserve for the actual show.
Don't panic if your star appears indifferent at this point. They're feeling their way, waiting to find out if you and your crew come up to their own professional standards. They are about to expose themselves on your stage and you can either make them look like the stars they are, or cause them and your audience considerable embarrassment.
They will also feel more comfortable if the script is written in a style and language that sounds like they do. How you'd write for Stephen Fry is not how you'd write for Joan Rivers.
And remember, you are not buying these people "by the minute". You're paying to have their celebrity status associated with your event, and by letting them do a comedy spot or speech that's out of proportion to the rest of your event programme, you won't get any greater value - you'll simply overexpose them. Always leave your audience wanting more.
To sum up then: if you treat your stars politely, confidently and professionally, they will respond.
DON'T LET IT HAPPEN TO YOU ...
An event manager failed to lay down ground rules for a radio presenter host at an awards ceremony. The latter swore repeatedly and insulted far too many people, to the extent that the chairman of the judges threatened not to pay him. The event manager assumed he would be the same as he was on the radio, while the presenter thought he was expected to be rude in order to be entertaining.