Are u female? Let's say u r, well, you ahould wear sth that is dainty and decent but not that girly. That's what I think. In addition, oh pllease, wear sth that matches your style and looks gd on u! Ah, I almost 4got, wear sth that is comfy too, u dun wanna feel uncomfortable while hving a gd time, right?(Only freaks wanna stay uncomfy all night (or morning) long!!!Good time at the prom! (if ur really going)
I'm assuming you're female? There'll be girls who wear short, even very short prom dresses to be daring or different but the cold shoulder look with long draping skirt will be right up there in fashion. This style has a gap between the strap and sleeve of your dress. It shows off skin, but isn't vulgar.
Another trend will be the choker. Again, with long and sweeping skirt, the choker draws eyes to your face. Be elegant and stick with a dress you'll be proud to look at in later years, not one that will make you cringe.