(BTW There is a great very-down-to-earth book called “Outside/Inside” from Targum Press about Tznius, if anybody wants to read it)
I highly recommend this book, along with every other Gila Manolson book. They are simply amazing. She has speeches on her website, as well as on simpletoremember dot com, all which are worth listening to.
There is a certain refined characteristic that every Jewish person intrinsically has, and this trait should shine through in every situation, not just mode of dress. The challenge is that it comes from the inside, and it’s up to you to figure out how to let it shine through.
I had a teacher in HS who claimed that she was able to tell who watches movies and who doesn’t according to how a girl holds herself and how she walks and talks etc. (I can’t say explicitly what she says cuz I want my post approved, but you can probably imagine where I’m headed…) Honestly no one believed her, but having been to both sides I must say that I know how these things affect you subconsciously. Walking, talking and just your general disposition can be very negatively affected by what you’re used to seeing and hearing, which is where the walking, talking and acting b’tznius fits in.