What you do at the back depends on how much hair you have. Medium length hair could be tucked into a messy bun or twisted into a chignon. It’s easy to secure shorter hair with bobby pins so have some fun with it. For short hair, just style hair as usual or sweep longer bangs to the side.
And for the cherry on top, the hair accessory! Find one that complements both the color of your hair and prom dress. Above, the dark royal blue is stunning with auburn hair and a bright blue accents on the dress. Feathers, flowers, or sparkle will all look great!