A transitional coat may sound like an indulgence, and that's precisely what this utility jacket by Burberry Prorsum is—and isn't. Made of rich, bonded felt and sporting patch pockets, it's effortlessly stylish, but it's also hardworking and versatile. It's a quintessential layering piece, ideal for crisper temperatures when worn over a T-shirt or a sweater. Of course, when it finally does snow, you may just want to add a scarf and keep it in the rotation.

Jacket ($1,795) by Burberry Prorsum. T-shirt ($90) by Wings + Horns. Jeans ($195) by Rag & Bone. Shoes ($575) by Burberry.

There's no bigger decision than what to wear over your suit, Monday through Friday. The updated single-breasted overcoat just happens to work on the weekends, too.

From left: Coat ($4,980) by Valentino, shirt ($200) by Acne Studios, T-shirt ($25) by J.Crew, sweatpants ($185) by T by Alexander Wang, shoes ($150) by New Balance. Coat ($795) by P.S. Paul Smith, sweater ($108) by J.Crew, jeans ($390) by Public School, shoes ($545) by Armando Cabral. Coat ($498) by Kenneth Cole, suit ($3,150) and shirt ($360) by Bottega Veneta, tie ($195) by Burberry London, shoes ($1,000) by Hermès.

1. Even without the chic leather detailing, this trim navy overcoat would be the kind of approachable, high-fashion piece you can throw on with a pair of sweats and sneakers and still look dressed—as opposed to dressed for the gym.

2. The beauty of a well-tailored gray peak-collar overcoat like this Paul Smith version is that it will never feel dated or out of place. Wear it with blue jeans and a sweater (like this guy) or just about anything else in your closet.

3. If you're going to wear a suit, cover it with a top layer that's just as sharp—and well-fitted. This classic charcoal version falls perfectly: The hem hits mid-thigh and the overall silhouette is slim.

No longer a gym staple, the classic sweatshirt makes for an indispensable layer when the weather cools off.

Clockwise from top left: Shipley & Halmos ($165). Ami ($210). Reigning Champ ($130). 3.1 Phillip Lim ($295). Todd Snyder ($175). Stone Island Shadow Project ($310).

There are wardrobe basics, and then there are those lust-worthy staples that make the transition from the depths of summer to fall's crisper months seamless. This Prada sweater is one of them, made of Shetland wool and cut narrower than more classic crewnecks. It's another reason to root for the mercury to drop.

Sweater ($480) by Prada.

Grunge Makes a Comeback
The flannel shirt—cut trimmer and made to be worn, not tied around your waist—gets an update from designers with a soft spot for nineties-era grunge.

"Flannel shirts never truly go out of style. They just keep being reinterpreted over and over again. Ours is overdyed, then sprayed, and then baked to give it a harder edge."
—Public School designer Dao-Yi Chow

From left: Saint Laurent by Hedi Slimane ($890). Rag & Bone ($290). A.P.C. ($235). Public School ($325). A|X Armani Exchange ($88). Band of Outsiders ($295).