One thing I found very interesting about the DC prep aesthetic is that you could spot the kids who spent summers in Europe from a mile away.
So, as I stated, the customary DC douchebag uniform (you see this guy at Chaddie's, the Tombs, and all the other Georgetown haunts) is topsiders, short/rumpled khakis, BB OCBD, and a somewhat ill-fitting PRL or Press blazer with gold buttons. If PRL, it was acquired from the Polo store on M Street at full price using daddy's Amex. If it's Press, it was a gift from an uncle.
But the kids who summered in Europe - especially France and Italy - learned what it means to add a dose of sexy to the preppy. So, swap out the topsiders for some killer handmade loafers or double monks. Swap out the khakis for some dark denim, just short enough to expose the shoe. Slim down the OCBD. The PRL blazer gets swapped out for patch pocket navy Kiton blazer with horn buttons. And what you have is a really, really great look that's faithful to the preppy aesthetic but still looks sharp in Paris.
Sid Mashburn is basically minting money off of this concept in Atlanta, and my guess is that he opens a DC shop in 2 to 3 years. Smart man.