In the 1920s the 'modern' generation wore dresses with shorter skirts and no waistlines. Men became clean shaven and women cut their hair short and got permanent waves. That was my mother's generation.
When I was a kid we went back to full skirts with petticoats and wide belts. While our fashionable clothes weren't as long and restrictive as those in our grandparents' day, we valued the old fashioned look. Things worn in the previous century like cowboy gear and coonskin hats also became popular. For a while, some boys even wore Mohawk hairdos, though most had crew cuts and lots of girls still got perms.
Then came the hippie generation with men growing long hair and facial hair again. For the first time (probably because of mini skirts) women and girls could wear pants to work and school. Some styles imitated things from other cultures.
Today the grunge look is in, and my grandparents would be horrified to see the body parts freely displayed in public by both sexes.
But all things change and I'm guessing that the new generation will swing the other way.
While spiked hair is not uncommon and I've seen a few young teens wearing wide belts and full skirts, that doesn't mean they'll go back to clothes like we had in the 1950s. I doubt that women will ever return to wearing skirts and dresses all the time, but perhaps the kind worn in the middle ages will become popular when they want to dress nicely. Maybe clothing will imitate a sci-fi or fantasy world. Or perhaps togas, sarongs or kimonos will become the norm.
It will be interesting to see what's in style ten or 15 years from now, but it's certain to be different from what young people wear today..