Interesting thread.
I don't think I would ever let a daughter of mine wear an outfit that screams to the world "Look everyone, I'm a sex object!" Nor am I going to make her wear a habit. Nonetheless, any daughter of mine will surely be a ravishing beauty just like her mother, and therefore turn heads regardless of how she's dressed.
With younger kids, mom or dad has to take them shopping, and that means mom or dad can lay down the law as to what is appropriate and what is not. Sadly, this isn't as easy as it used to be, both in terms of finding appropriate clothing and in terms of dealing with the kid's temper tantrums when you won't buy her a micro-miniskirt. When the kids get a little older, you can explain to them why you won't buy them the hip huggers and midriff-baring tops.
Teenagers usually pick out their own clothes and have their own money to spend (from an allowance or job income) so mom and dad get less say. Hopefully by that age, the "don't dress like a hooker" message has gotten through, and the kids will be choosing outfits that say "Look at me, I'm a young woman/man" but not "Wouldn't these clothes look good on your bedroom floor?". At some point you have to trust your kids to make their own decisions about how they will dress, just like you have to trust them to make their own decisions about everything else in life. As adults, they will have to make these decisions on their own every day. As teenagers, they can start making them, subject to parental veto.
I practically grew up in a convent
so I will most likely give my hypothetical future children a lot more leeway than I had. But there are plenty of outfits I've seen in stores and on people around town, that if my hypothetical future 16-year-old daughter were to try to leave the house wearing, I would be sending her upstairs to put on the rest of her clothes.
The same goes for my hypothetical future 16-year-old son - if he wears something inappropriate, he gets sent upstairs to change, too.