1st: Consider YOU, YOURSELF and YOUR style! Do you want to be a more flawless YOU, do you want to be more glamorous, or are there any traditional looks you want to have? You will have a lot of eyes and cameras on you, so you want to have a look that you feel good with.
Another way of looking at it is, how do you want to look in your photos 10 years from now, 20, 30, and so on, as these are going to be memories for generations to come!