Today is the first official day of fall, my favorite of the four seasons—the air is crisper, the leaves change to gorgeous autumnal hues, and sweaters and boots (check out our faves this year) come out of storage. What better way to celebrate than with a style makeover? Chances are you're as sick of your summer office outfits as I am. We've got 10 ways to shake up your work look with fall's top trends. A new season is also the perfect excuse for a hair change: Check out the top 10 haircuts and colors right now! And for an instant mood lifter, put your whites in storage and try on fall's hot new hues, like cobalt blue, bright red and purple. Finally, if a new wardrobe isn't in your budget, shop our favorite fall accessories under $100—Meg Ryan's messenger bag, bowler hat and gloves made her look in this scene from When Harry Met Sally. And pssst, beauty mavens, don't miss the best new beauty finds under $15 bucks!