1. Sienna Miller
The temperatures are beginning to heat up, which means some of your favorite celebs are exchanging their winter layers for refreshing, spring-ready ensembles. But of all the recent warm-weather outfits, you were most inspired by Sienna Miller's easy mix. The darling actress stepped out in London earlier this week wearing a white AllSaints dress and Hudson combat boots. We like the way her utilitarian footwear tones down the frock's sweet and girly vibe, giving the whole look a slightly '90s, grungy feel. To finalize her breezy afternoon ensemble, Miller accessorized with Sanford Hutton sunglasses and a Botkier bag. To execute a similar combo, start with Topshop's Cream Chiffon Flower Applique Neckline Dress ($85) or Nasty Gal's Daisy Crochet Dress ($58); they're both excellent pieces to have on hand this summer. To further achieve Miller's winning look, style your frock with Goldyn's Ashland Boots ($90) in Tundra and Raen's Sunglasses ($95) in Seaglass/Smoke.
2. Michelle Monaghan
If you're looking to make a statement with your next after-hours look, why not try a daring cocktail dress a la Michelle Monaghan? The brunette beauty looked stunning last week at the New York screening for her latest film Source Code in a teal Roksanda Illincic dress from the designer's S/S 10 collection. The frock is a visually intriguing choice, thanks to its awe-inspiring color and asymmetric hemline. To finish her stellar evening look, Monaghan selected a pair of braided Chrissie Morris platform sandals and a Jimmy Choo clutch (similar styles are available at Jimmy Choo boutiques nationwide). Fortunately, it's rather simple to recreate Monaghan's red-carpet look. If you're a fan of that gorgeous teal hue, definitely check out Calvin Klein's Jade Sheath Dress ($89), while those of you who fancy an untraditional silhouette will surely appreciate Rare's Opulence Poppy Train Dress ($330). As for the footwear, we think Steve Madden's Bonndd Wedges ($80) and Joe's Jeans' Diva II Strappy Platforms ($220) are both worthy contenders.
3. Gwen Stefani
There are two reasons why we were beyond thrilled to see so many inquiries about this fabulous Gwen Stefani ensemble. First, we adore the singer's incredibly cool sense of style and second, we're completely smitten with the '70s-inspired outfit she put together for a dinner in Los Angeles last week. Stefani was snapped in head-to-toe L.A.M.B., specifically a silky blouse and wide leg pants from the F/W 11 collection, plus the Noss Boots ($395) and Brunswick Honey Satchel ($278). Additionally, we like the way she punched up her look with bright pink nail polish and lipstick--both smart beauty choices for spring! If you're looking to construct a similarly savvy ensemble, style MICHAEL Michael Kors' Black Cowl Neck Zip Back Blouse ($70) with Robert Rodriguez's Tencel Wide Leg Pants ($295) or simply pick up a one-piece, like Marc by Marc Jacobs' Simone Silk Jumpsuit ($348). As for accessorizing your outfit, be sure to grab Loeffler Randall's Fifi Boots ($250) and Marc B's The Olivia Bag ($98) to get a perfect, Stefani-inspired look!
4. Whitney Port
Whitney Port has a knack for putting together ensembles that are both polished and effortlessly intriguing. Take, for example, the outfit she wore to the Directives West F/W 11 runway show in Los Angeles last month. The designer/author/style star paired a gray 3.1 Phillip Lim shirt and Muubaa leather pants with a striped blazer from her own Whitney Eve collection. Printed jackets are not only visually interesting, but they also offer a simple way to liven up your understated pieces. To further elevate her look, Port accessorized with an oversized gold necklace by Mawi London and Jimmy Choo sandals. If you want to snag some similarly standout pieces, we suggest checking out Tart's Camryn Jacket ($172), Elizabeth and James' Jagger Linen Blend Jacket ($395), and Juicy Couture's Drama Necklace ($178) right away.
5. January Jones
Whether it's a head-turning red-carpet dress or a laidback off-duty ensemble, January Jones has a knack for creating memorable looks. Speaking of the latter, the gorgeous Mad Men star recently caught your attention wearing a green, yellow, and black striped Gerard Darel sweater (similar style are available at Bloomingdales) while out shopping in Los Angeles late last month. In addition to the bold-stripe top, her 7 For All Mankind Georgia Jeans ($189) in New Zealand are in perfect keeping with the season's top denim trends. Finally, to add a touch of chic to her casual afternoon outfit, Jones accessorized with Givenchy's amazing Large Antigona Tote ($2245). If you'd like to create a likeminded look, start with Marc by Marc Jacobs' Schooner Stripe Top ($148) or Lacoste's Wild Stripe V-Neck Tee ($60). Next, pick up the actress' exact denim pick or try Gap's Vintage Flare Jeans ($70) in Hermosa, which is a superb look-a-like style. Once you have your clothing sorted, it's time to pick a bag! We recommend checking out Furla's Cassia L Shopper ($395); it's a chic carrier that's an ideal choice for a day of shopping.--Jessica Baker
Photos of Sienna Miller and January Jones, courtesy of Bauer Griffin, Photo of Whitney Port, courtesy of Getty; Photo of Gwen Stefani, courtesy of Wenn