Honestly, this has been something on my mind as well.
My parents never allowed me to wear dresses/skirts that were short...like above the knee in public. If I were to wear one...I had to wear it with a legging. It was annoying for me...coz I preferred to wear dresses that were short and didn't understand why they were so strict about it. But, eventually I understood why certain clothes aren't suitable as a Christian.
Though, I see a lot of Christian girls who wear stuff like crop tops and shorts. And there's nothing wrong with that. As long as you're respecting yourself

I love wearing shorts and crop tops but sometimes it depends when you're going out and whom you're gonna be with. I'm still not allowed to show off too much skin

even if I 18...and it's annoying...coz I feel myself when I wear certain clothes and other clothes that are bit too old fashioned I feel restricted.
Anywayyyy, this isn't about me.
In conclusion, generally, wear appropriately of course. And something that makes you feel comfortable and respected. Dress like a daughter of a King, if I can say that.