Listen to the opinions of your mom and/or friends as to what styles and colors look good on you. Just because you like the dress in an ad doesn’t mean it’s the dress for you.There’s no way to guarantee that you’ll be the only one at prom with your dress since girls buy from bridal shops in neighboring towns and also online.
Pick dresses a size larger than normal. Prom dresses run at least one size smaller, just like wedding gowns. Remember to always try it on. Or at least try a similar style, if they one you want isn't in the right size.
Then Try on lots of different styles of dresses. You might love a dress you never thought you'd wear. Almost every prom dress will need some alterations for a perfect fit. Always buy your prom shoes before your alteration appointment so the dress can hemmed to correct length. Let your friends know which dress you buy so that they will be able choose another style.
Last, Consider buying your accessories and shoes at the time you buy your prom dress. You'll have the dress on when trying on jewelry and shoes so you can see the complete look before you buy.