The University of Miami is not a campus with visible school spirit, just visible tan lines.
Like everything else, Preppiness begins in the home.
Preppy clothes are built to last, since they certainly won't go out of style.
Wool, cotton, and the odd bits of silk and cashmere are the only acceptable materials for Prep clothes. They look better. They require professional maintenance. They are more expensive.
In a true democracy everyone can be upper class and live in Connecticut.
A tip: if you're invited to your friend's country club to go the lost and found bin and pretend that you left something there. Next thing you know, you have a fabulous sweater.