I have long hesitated as to whether I should write this post or not since it's probably better not to dwell on the certain things too long. I'd also like to put a disclaimer that what I'm going to say is sorely my opinion, and you don't have to agree with it.
Anyway, here goes. All traditional cultures value modesty for women, especially for young fertile females. (Modesty standards usually relax a bit as they get older). Some cultures, such as Mid-Eastern ones, are probably going too far in our opinion, but before the West became so liberal, women were expected to wear long (sometimes floor length) loose skirts/dresses and some form of a head-covering. Unmarried women in some situations could go bare-headed, but only women of the streets would let their hair loose.
This modesty concept isn't restricted to monotheist religions only, since in Ancient Greece "decent" women were usually veiled and ditto in Rome. What is the reason behind all these customs? Serious researchers (as opposed to muh misogyny crowd) will usually say something about how dangerous it was for women in primitive societies to show their beauty as they could be attacked, kidnapped, sexually abused etc. (The religious reasons would be as not provoke sexual passions of men).
Yet, even relatively safe societies where women could go about their daily business unmolested, had similar traditions. Plus, even in our decadent times, most people still don't go naked in the privacy of their own homes, where theoretically, nobody can see them. It's still imprinted in our minds that full nakedness is something shameful and should be reserved for the bedroom only.
Here's where it gets interesting. If you have read any of the ancient myths and legends, you'll come across stories of "gods" and supernatural beings falling in love with beautiful girls. Sometimes, their fathers will lock them up in a tower, but some "hero" will still find a way to climb that wall.
I remember an Irish legend of a young girl playing outside in the town square with other children (safe place + the girl is still a child albeit a beautiful one) who gets stolen by a very handsome stranger who comes out of nowhere and disappears in the same fashion. Later, the parents find out that it's some god who stole their daughter to take as his wife. By this time, she already has a son from him. Etc etc.
Of course, Genesis tell us the story of the "nephilim" which I guess every Christian knows about and then, there is the (in)famous Book of Enoch (please don't let your children google it!). That is something I honestly don't care to go into detail about, by various reasons. Anyway, if you say it all happened before the Flood, Catholic Apocrypha (I think the Book of Tobit though I could be mistaken) deals with the same topic.
And then, you have the passage which tells us that women should cover their hair while praying or prophesying "because of angels", which is really never satisfactorily explained anywhere, though sometimes it's said that uncovered female hair is seductive, will distract men in church from their prayers etc. Yet, it's not said that a woman should cover her hair because of men if you see my point. By this reason, Amish women are supposed to wear some sort of a head-covering the whole time, even in the privacy of their own homes.
The bottom line is that modesty is the matter of conviction and heart. I'm not going to give you any guidelines to follow. There is one point I'm going to make, though. When a woman chooses to wear something seductive and put on tons of makeup does she ever think of who or what may be lusting after her?