First, let us make one thing clear: There is no one set uniform for the fashion month crowds. It's really an exercise in personal style—a wardrobe marathon, if you will. It should be about wearing what you feel the best in while saving time and constructing outfits that keep up with your busy schedule—that's a concept any grown-up can get on board with, whether or not you're attending this major industry event.
Each city has an unofficial dress code of its own, and it may be that one fashion capital relates more to your closet than others. Note the sartorial nuances: In Paris, you'll find that renowned French chic (it's not an urban myth, you know) while in Milan you can expect to see far more flamboyance and frills. But what can be said for London?