Here are some of my favorite ethnic dresses for women. You may or may not want to actually wear this, but this certainly can give you some new ideas.
Vietnamese Ao Dai
Vietnamese ao dai comes in all colors and basically consists of wide pants and a long shirt. There are modern versions of ao dai but even traditional ones look very wearable.
Ao dai comes in all colors and textures, from everyday ao dai to evening gown-like ao dai.
Moroccan kaftan is my other favorite. Colors and textures can vary too, but all versions will emphasize waist.
Traditional hanbok means high waist and a lot of volume. While traditional hanbok may make you seem larger than you probably want to be, modernized hanboks can make an excellent evening gown or even wedding dress.