When I was a teen and going through my hippie phase, I dressed like you might imagine, torn, ratty jeans and hiking boots and long indian dresses and sandals, but I did always wear a bra...no bra burning for me! Anyway, my mother would have done anything to get me to go shopping with her at Filenes(our local department store) and buy me clothes. I would have none of it. And to her credit, she never refused to "take me out in public" in my chosen garb, not even to our temple high holy day services, or attending a Saturday evening concert with her at the Boston Symphony. There I was wearing my beloved jeans or long dresses. She made a very conscious decision that having my company outweighed whatever embarrassment she might have felt or judgement she imagined her friends had of her child. And she had to deal with this times two. My older brother had hair down to his waist and a straggly beard. His alternative style was accepted as well. We were still really nice kids. Our clothes did not change that, and my mother got that!
Perhaps you have a teen that is "expressing" themselves in a way that makes you crazy. Here's my bottom line. If its not disrespectful or unsafe...so be it. But if a tee shirt sports druggie talk, swears or other disrespect language, take a stand. They may choose to wear it with their friends, but because this article of clothing could offend..not with you! If you have teen daughter who is wearing sexually provocative clothing. It's also appropriate for you to step in. That kind of clothing could potentially send off signals to boys and men that your daughter might not intend, and get them into situations they may not be able to handle.
Other than these two bottom lines, it's your teen's prerogative to develop their own personal style. They are trying on different persona's all in the search for an identity. And it probably is not your style. But that's good, cause they aren't you!!!!Don't worry, it will change next week!