By modest, I mean shorts/skirts that reach down to the knees or lower, tops that don't show cleavage, tops that aren't skin-tight or transparent, no belly tops, jeans that fit well but aren't skinny jeans...
By nice, I mean clothes that are clean, in good condition, that go well together, which are colours that suit her...
Her hair is done nicely and she is wearing a light amount of make-up that looks natural.
I, personally, am extremely attracted to girls who dress conservatively and sit up right and who allow me to behave old-fashioned without the skepticism being a gentlemen gets you nowadays. I would go so far as to say, turtlenecks, blazers and scarfs are more physically appealing to me than short shorts, undersized t-shirts and visible underwear.
Now you may think that is all inference of personality, but sex appeal is directly related to mental attraction. Ergo, if I strongly dislike dumb girls, I may lose a lot of physical attraction as soon as they speak. Or on the other hand, a girl who shows off how artsy she is, immediately dictates physical attraction from me.
But this is just me. What do I believe is the most honest answer?
If you're physically attractive (great facial construction, complexion and hair) dressing conservatively makes you 10x more attractive than sleazy clothing since it highlights the most important aspect of beauty-- your head. If you're on the uglier side, revealing clothing gives you a greater edge since it highlights your body over your face.
As you can see, Greg Plitt should just keep his shirt off at all times cause his face doesn't compete. So basically, the general strategy here is to extenuate your sexy face by dressing conservatively, or mask it's blandness by revealing your sexy parts.
I find modest women to be far more attractive than women who let it all hang out. Modesty is a sign of self-respect and confidence. Women who wear short shorts and skirts and show off crazy accounts of cleavage are just desperate for attention and self-validation.