“I had to completely change my wardrobe when I moved back to DC from New York last year,” says Katie Rost, a twentysomething model who grew up in the District and Maryland. “The look here is more polished and conservative. I’m starting to develop an appreciation of clothes that make me feel timeless.”

Besides modeling occasionally, Rost works for her family’s Ronald F. Rost Foundation, which serves children in need. She also has launched Body by Katie Rost, a line of all-natural scrubs, creams, and bath salts (bodybykatierost.com).

Rost, who’s been on the pages of such fashion magazines as InStyle and Glamour and has walked the runways of Paris and New York, talks about what she’ll be wearing this spring.

Her style: “Simple, sporty, and comfortable. Because I travel all the time, I like clothing that can be thrown in a suitcase and look cute without a lot of ironing.”

Favorite designers: Stella McCartney, Marc Jacobs, Ralph Lauren.

What she’ll be buying this season: “I still like a bit of the ’80s look—slim-fit, tapered jeans with heels; fuller shirts with cool belts. I love the bold prints and flowing dresses from Gucci’s spring show. For cute but cheap knock-around clothes, I will always be a J.Crew girl. I recently modeled its spring/summer line and fell in love with all the preppy plaid shorts and sweet pinstriped clutches. J.Crew also has simple strappy sandals in silver or gold.”

What she’ll wear that’s already in her closet: “My Pucci dresses and skirts.”

Where she shops: Barneys Co-Op and Jimmy Choo in Chevy Chase. Also online for shoes, “usually Saks Fifth Avenue and Neiman Marcus. I just ordered some ballet flats from Toryburch.com.”

Daytime wear: “Jeans—Chloé is my favorite, but also American Eagle’s ‘boyfriend’ jeans for women, Michael Stars tank tops, and Havaianas flip-flops.”

Evening look: “Marchesa gowns—I like the feminine, whimsical looks they did this season.”

Spring splurge: Bottega Veneta’s Intrecciato Nappa Tote, a slouchy woven leather bag. It’s $2,650 at Saksfifthavenue.com.

Beauty favorites: C.O. Bigelow Mentha Lip Shine; Chantecaille Butterfly Eye Shadow in Rose.