I havent ever planned one, but I have been to a few, and I know what goes on. The ones that we have on our campus, are normally benifits, rasing money breast cancer. There normally arent any prizes, but if you wanted to do prizes you could either do gift cards, or cute "sister deeds", like the winner gets to have their laundry done by a sister for a month.
The night normally goes like this...
They have a introduction, where the boys come out dressed as the theme of the night, like beack wear. They come out and introduce themselves, with a little speech.
Next there is a talent portion.
After that the panel of judges voted for their top five and you announce that.
Then the top five answer a question, and the judges vote who the winner is....
Hopefully this helps you a bit
