Princess dresses for prom and 18th birthdays – a guide to the most fashionable styles. Proms and 18th birthdays are two special events that deserve a unique setting. It's no wonder, then, that more and more girls are choosing princess dresses for prom and 18th birthdays, distinguished by tulle, corsets, and fairytale cuts. Check out the most fashionable designs that combine elegance, lightness, and a striking look. Why?