Alyson Hannigan

We challenged Alyson Hannigan, star of TV’s popular new show How I Met Your Mother, to an afternoon of shopping. Her goal: Find the coolest clothes to wear this season, whether you’re in Hollywood or your hometown.

To explore the hottest styles for spring, this year we turn to the small screen. We asked Alyson Hannigan, 31, to take us shopping for her character on CBS’ popular new comedy, "How I Met Your Mother" (Mondays, 8:30 p.m. ET).

"I was such a tomboy when I was growing up," the actress confesses gamely. "I had no fashion sense. It wasn’t until my 20s that I actually became a ’girl.’ I feel like I need to make up for all the time that I’ve lost. So I’m hitting the stores hard!" Cover: Allison Hannigan Clothing: Dress: Corey Lynn Calter; trench coat: Burberry Prorsum; vintage necklace: Platt Boutique Jewelry, L.A.

In real life, Hannigan loves designers like Marc Jacobs and Chloé, but she also heads to the racks at Urban Outfitters and Target when she needs a fashion fix. "I’m not obsessed with labels," she says. "I bought the cutest hat [at Target] for, I think, $9.99, and I got so many compliments! I’m all for Target."

On "Mother," Hannigan plays Lily, a 20-something New Yorker who spends her days as a kindergarten teacher and the rest of her time hanging out with her fiancé and their wacky friends.

Keeping Lily’s schoolteacher salary in mind, Hannigan and "Mother’s" lead costume designer, Susanna Puisto, took us to the fashionable Third Street Promenade in Santa Monica, Calif., to assemble three smart looks for spring: one Lily could wear to work, one she could wear on a Saturday afternoon, and one she could wear to a party with pals.

Because of Hannigan’s fair skin and red hair, Puisto likes to dress Lily in jewel tones. But for style inspiration, she looks to hipster starlets Sienna Miller and Chloe Sevigny. "These girls make trends. They don’t play by the rules," Puisto says. "And Lily is a New Yorker. She has an urban look, but it’s still a little playful."

Soon enough, we had three great mix-and-match outfits that capture the essence of this season. We think these picks — and Lily’s cute-meets-funky style — will inspire you this spring, as well: