Here is another good article on the topic of modesty of dress:
Modesty of Dress and Love of God
Immorality in Fashions and Destruction of the Family
Garb that does not show a person’s self-respect as an intelligent and free being (and, through baptism, as a son or daughter of God and a temple of the Holy Ghost), contributes to a large extent to the present destruction of the family. It does this by favoring temptations against purity. It also does this by its vulgarity and childishness that corrodes the notion of the seriousness of life and the need for ascesis (self-discipline), all of which are fundamental elements that maintain family cohesion and stability.
The struggle for the restoration of the family by opposing abortion, contraception, and homosexuality will be much more effective if done together with efforts to restore sobriety, modesty and elegance in dress.