The Three-Layer Rule

Stylists build most outfits in three layers: a base, a middle, and an outer. The base sits closest to the skin and stays thin and fitted. The middle adds warmth or texture. The outer frames the whole look.

Here is the rule in one outfit: a crew-neck tee as the base, an unbuttoned oxford shirt as the middle, a denim or leather jacket as the outer. The tee shows at the collar, the shirt drops below the jacket's hem, and the jacket holds the shape. Three plain pieces, one finished look.