18. The Tuxedo-Style Blazer — If you don't already own one of these, shame on you. Because if there's anything we've learned from Yves Saint Laurent, it's that Le Smoking is the coolest look on a woman, ever. And fall's tuxedo-style blazer is the perfect way to infuse that timeless brand of chic into any outfit. 

Nasty Gal Moto Blazer, $78, available at Nasty Gal; Helmut Lang Smoking Tux Blazer, $575, available at Forward by Elyse Walker.