Boyfriend Sweater = Closet Staple Pair one of fall’s favorite trends, leather leggings, with a slouchy boyfriend sweater for the full effect. Erin – photographed at The Ritz-Carlton, Westchester in White Plains – wears Vince leather leggings, $1,150, with a mustard Diane von Furstenberg sweater, $465, and Jimmy Choo studded smoking slippers, $650.

Shades of Gray Prevail Comfort meets couture with Burberry Prorsum’s stretch tweed dress, $2,995, with Christian Louboutin’s gorgeous burgundy suede booties, $995, and Celine’s coveted, structured doctor bag, $2,300

Sporty, Sexy Style Erin balances the sportiness behind Stella McCartney’s scuba dress, $845, with the sexiness of her Jimmy Choo mesh booties, $995, and Herve Van Der Straeten earrings, $425.

Ladylike Meets Men’s wear Erin puts a perfectly Parisian twist on her men’s wear-inspired ensemble. She taps her toes in fabulous silver and patent leather loafers by Lanvin, $770, which accent her Rag & Bone jacket, $535; blouse, $350; and pants, $290; and Kara Ross bracelet, $195.

The Power Purse Conquer the boardroom in Cucinelli with luxurious trousers, $775, and an ultra-soft sweater, $995, and hat, $330, plus Fendi’s knock-out bag, $2,260, and Marni bangles, $350 and $420.

Creatures of Comfort Erin takes a walk on the wild side in a fall-ready emerald fur vest, $1,795, cashmere and wool sweater, $295, and leather leggings, $1,150, all by Vince; a Gucci satchel, $2,650; and Kara Ross bracelet, $195.