Check out these tips:
Be Thrifty: Visit your local thrift store. There are many dresses to choose from at your local Goodwill or Salvation Army. This is a real bargain. Who knows you may find a dress for under $20?
Go Vintage: If you have a dress already, you can kick it up a notch by getting some great accessories. Go to a local antique shop to get some unique jewelry or clutch-style purse. This way, you’ll be guaranteed to not have a twin on Prom night, who also purchased her accessories at Target or Old Navy.
Shop at Home: Take a peek in your mom’s or grandma’s closet. They may have some dresses you can remix with your own style. Add a belt, shorten the length or make it sleeveless for a new look.
Go Bridal: Search the clearance section of a local bridal shop, department store in-person or online and look for discounted bridesmaid dresses. I bought a few dresses for dances this way in high school. It may be Prom, but it does not mean it has to be labeled a Prom dress.
Go Local: If there is someone in your school or in your ‘hood with sewing skills, see if they will make a customized dress for you. Word of advice though, make sure you look at examples of their work and have a strict deadline to get your dress on time.
Support a young designer: Colleges like FIT (Fashion Institute of Technology) and Parsons have young designers who would love to gain more experience in making clothing. Contact a local school and you may get a dress designed by someone whose fashion may one day grace the pages of Vogue magazine or may be worn by a celebrity at a red carpet event.