As Monday’s Met Gala approaches, the art of fashion is top of mind — and celebrity stylist Erin Walsh is breaking down her process.

On Thursday night, the stylist hosted a cocktail party at The Fifth Avenue Hotel’s Portrait Bar in celebration of her new book, “The Art of Intentional Dressing.” Anne Hathaway, who penned the book’s introduction, served as a cohost for the evening. The actress, on the eve of the official theatrical release of “The Devil Wears Prada 2,” was dressed in a black crepe top and trousers by Stella McCartney for the occasion.

Other guests included actresses Ariana DeBose and Beanie Feldstein — who are both styled by Walsh — as well as designers Stella McCartney, Prabal Gurung, Fernando Garcia, Jennifer Fisher, Fletcher Kasell and Tanner Richie.

“The Art of Intentional Dressing” has been 10 years in the making, as Walsh realized that many of the women she was dressing approached fashion with the same insecurities. “ I wanted to turn that around, because I knew the empowering possibilities of embracing fashion,” said the stylist, who started writing the book in earnest during the pandemic. “ I wanted it to feel like a French pocketbook,” she added. “Something you can literally take with you, and it’s like your little successful, practical guide.”

Copies of the compact book were displayed around the room at the Portrait Bar, inviting guests to page through as they sipped Bulleit espresso martinis.

In the lead-up to the book’s release, Walsh has enjoyed seeing how people have put the book’s advice into practice. “People have been DMing me on Instagram their videos, and how their lives are changing because they’re getting intentional about fashion,” said Walsh, whose “CREATE” method outlined in the book is informed by identifying three guiding words.

“I was feeling joyful, optimistic and elegant,” said Walsh, sharing the three words that guided her own fashion choice for the evening: a light pink feathered Oscar de la Renta dress.

Like many in the room, Walsh is gearing up for a busy weekend of final preparation ahead of the Met Gala.

 ”With this particular Met theme, it’s so weirdly in alignment with my book in terms of the art of fashion and your body and symmetry and alignment,” Walsh added. “It’s funny how synchronicities line up that way.”