i think it's really important to try to make sandy (or whatever your character in grease, i was rizzo) a real person. so many times i've seen grease and the characters are flat. sandy is JUST sweet. rizzo is JUST mean -- things like that. it's so much more enjoyable to watch, and seems so much less "fluffy" if you give your character more than one personality trait.
also, go into it understand that it probably won't be the most moving or meaningful role of your entire life....but have as much fun with it as possible, because as fluffy of a show as it is....it really IS fun to be in.
break a leg!
"grace, you're stuffed in a box getting rid of ass plaque. let's face it, this evening is a bust."