My kids are older, the oldest 23, youngest 15. Needless to say they each have their own style. I had one who was into the Gothic look, another into baggy, another into country and yet another more into jock. With so many, there were sure to be things I didn't like. My ds wanted his ear pierced and another wanted to dye his hair. Dsd loved the animal prints. Ugh.
With each, we allowed them to be their own person as long as it was presentable...no buts, boxers or panties showing. No clevage or high spikes. Piercing remained in the ears, etc.
I believe self expression is a part of growing up.
What is your children's style? Who picks it? Do you like it?