Length of your hair
The style that you pick will depend on the length of your hair.Start by separating your hair into 3 low ponytails. Then pin down each of the ponytails into a bun, they should all look like they blend in together. Add some elegant barrettes and your set. Always use extra hairspray to arrange the loose ends.
The Curlier the Better
A traditional hairstyle is to get them to wear their hair curly especially if your hair will be straight. Personally you should go with a French twist, it's nice and elegant and the style looks great on film.
Stay away from half pony tails or random conges. Get advice from other hairstylists in your area and make an appointment ahead of time. Also you may want to get your hair down as early as possible in case you don't like the style you have time to change it.