By now, most of you know our bimonthly What Was She Wearing drill. You send us your pressing celebrity style questions and we utilize our fashion editorial skills to uncover the answers! In this edition, we itemize an all-star selection of outfits worn by the likes of Nicole Richie, Mary Kate Olsen, and more. Enjoy, dear readers, and keep the requests coming!

Nicole Richie
The ever-so-stylish Nicole Richie is responsible for a large number of the requests we receive in our What Was She Wearing inboxes. In fact, her chic ensembles are so plentiful that we could easily dedicate a weekly column to the fashion master. Just last month, Richie wowed us in Rozae Nichols' Feather Printed Top ($230, 310.550.0910), a pair of cut off denim shorts, and Givenchy's Cut Out Booties ($765) while lunching at La Conversation in West Hollywood. She also showed off some of her own House of Harlow 1960 jewelry creations, including a Red Leather Mosaic Bracelet ($70), Black Leather Cuff ($125), Black Leather Sunburst Ring ($38), and Gold Triangle Headpiece (available next month). Emulate Richie's look with Edun's Althea Top ($215), Urban Outfitters' Urban Renewal Denim Shorts ($158), a Michael Kors Snake Chain Waist Belt and Charles David's Bracelet Heels ($215).

Mary Kate Olsen
We are exceptionally charmed by the latest outfit we've filed away in our Mary Kate Olsen database and more than happy to share the details with you! Olsen demonstrated enviable street style while running errands in Hollywood a few weeks in the Bed Jacket ($485, available in February) from her Elizabeth & James S/S 09 Collection, Rock & Republic Izzy Black Leggings ($98), and Proenza Schouler's Medium Tobacco Suede Bag ($1595, 310.276.4400). When creating a look like Olsen's, save yourself some dough by swapping out her purse with Urban Outfitters' Deux Lux Pintuck Satchel in brown and leggings with American Apparel's Disco Pants ($90).

Rachel Bilson
Since Rachel Bilson can wear no wrong, we rely on her as a regular subject matter in this column. Most recently, She was recently spotted leaving a cafe in Los Angeles dressed in a lightweight Juicy Couture Dropped Waist Dress, retro Marni boots, a vintage blue color jacket, and an antique ethnic purse. Take a cue from Bilson by warming up a summer dress from your own closet with Nine West's Gwen Bootie ($128), Urban Outfitters' Urban Renewal Boys Blazer ($58), and a West/Feren's Berkshire Bag ($175).

Sienna Miller
To conclude today's fashionably au courant round-up, we have the scoop on the threads Sienna Miller wore while at the Freize Art Fair in London last month. Miller walked through Regent's Park sporting a vintage Gap shirt, Chanel Jacket ($4710, 310.278.5055), a pair of Twenty8Twelve Skinny Jeans (they're no longer available, but try Delia's Morgan Low-Rise Grey Skinny Jean ($50), and an Alexander McQueen scarf. You can steal her style by cladding yourself in a Vince Crochet Trim Cashmere Cardigan ($335), a Heron Sheer Tee ($11) from Old Navy, Gentle Souls' Bay Leaf Flats ($195), and a We The Free Burnout Knit Scarf ($28) from Free People.-Jessica Amento, additional reporting by Claudia Codron