Great article on modesty in dress and manner over here.
It's rather long, so the highlights I enjoyed are below:
"we should prefer having certain things said in church, so long as it is taken from the Bible, than to have other things routinely done in church, things which are plainly condemned by the Word."
"But we have to be careful not to fight.... with traditional values instead of with holy Scripture. And the reason we do not use Scripture is that God’s Word condemns more than just immodesty—it also condemns many of "our little virtues." But pietism always drags impiety after it. In short, we have to fight immodesty in a scriptural way, and not by means of Victorianism."
"fathers and husbands today are simply not jealous enough."
"If in a particular society, wearing red meant that a woman was a prostitute, it would be immodest for a woman to wear red, even though the Bible says nothing against wearing red in itself."
"When others have an opinion on what you wear, they are not prying into business not their own. Clothes are a public act."
"With clothing, be mindful of lines of sight. Just as a painting done well draws the eye to a certain focal point, just as a wise architect knows how to draw the eye to certain places on his building, so the lines of clothing can do the same. Examples include unbuttoned blouses, tight jeans, or high slits in dresses. The issue is not what is seen, but rather what is indicated, whether out of sight or not."
"Many young Christian women must learn how to sit, stand, and walk like ladies."
"immodest women dress as though they hadn’t a clue about the effect they have. But other women panic over immodesty as though Christian men will be undone at the sight of a knee. Or two knees."
"When something goes wrong.... Th[e] illegitimate option, so natural to many, is to refuse to cover it in love, and also refuse to confront anyone about it. Instead, these folks go off in a corner and whisper about it critically and at length with all the wrong people. Either you speak to the person, or with those who are appointed to help you speak to the person, or to no one at all."
"women dress the way they do because it gets a desired response, and the young men are responsible for giving that response."