One afternoon recently, Marie Kondo, the thirty-year-old Japanese decluttering consultant and author of “The Life-Changing Magic of Tidying Up” (two million copies sold worldwide), had a few hours between publicity events to indulge in some shopping. She was in town for the Time 100 Gala—Jamie Lee Curtis had declared her “organizer-in-chief.” Kondo chose the flagship location of Anthropologie, in Rockefeller Center, a brand best known for whimsically bohemian dresses and floral bedspreads. “It’s very feminine and girly,” she said, through an interpreter. The KonMari method of tidying rests on maxims like “Discard first, store later,” and “Make tidying a special event, not a daily chore.” The next edition of Kondo’s book could include an appendix: the KonMari rules for shopping.

Before you start, visualize your purchase.

“I have an image in my mind of what I want, whether it’s a light jacket or a one-piece,” she said, one hand gently perched on a stack of blouses. In the store’s main entrance, she posed for action shots taken by her husband, manager, and photographer, Takumi Kawahara. “I can tell if what I want is in the store right away.” Kondo aims to shop only when the need arises, but admitted that spontaneous trips do happen.

Every item of clothing has a different role to play.

Shopping begins with a choice: “Is this for my business life or my private life?” Kondo wore a white three-quarter-sleeved, fringe-trim tweed blazer over a white ruffle-hemmed, knee-length sheath dress, black tights, and black patent-leather kitten heels. In her professional capacity, she always wears white, for its association with cleanliness and tidiness. “It is part of my brand,” she explained, “my image color. It is easy to recognize me.”

Be sure to handle each item.

Kondo’s criterion for deciding whether to discard or keep an item is the same for purchasing: we should feel a thrill of joy when we touch it. She stopped in front of a display of long-sleeved blue-and-pink rayon Maeve shifts, scrunching the rayon in her hand. “I have to touch everything,” she mused, fondling her way across the racks, feeling for joy. She chose a Paper Crown + Rifle Paper Co. spaghetti-strap robin’s-egg-blue dress with red posies and pink flowers and handed it to Kawahara.

Do not consider clothing that does not come in your size.

“Because I am very short, the first thing that I worry about is will they have my size. If a piece is too long, I don’t look at it.” Upon discovering the petites section, Kondo found an even smaller version of the size 2 blue-and-white scalloped dress by Eva Franco she had chosen from another section of the store.

Discard any clothing that no longer sparks joy.

Passing a display of denim jeans and dark-blue chambray shirts, Kondo touched almost nothing. She said that she rarely wears pants because several years ago they stopped bringing her joy.

Go through the whole store first and collect all the items you want to try.

Before descending to the store’s lower level, Kondo exclaimed, “This is a huge store!” She picked up a short sea-foam-green robe embroidered with red polyester flowers and remarked, “I usually don’t select this many items.” Her husband was holding ten hangers. “This is very rare.”

Don’t let your friends see.

A successful shopping excursion involves a large volume of clothes, which can be stressful for any friends or family waiting on you. Kondo prefers to shop alone, but is sometimes accompanied by her husband, whose opinion she asks even when she has made up her mind. An attendant in leopard-print heels arranged the dresses in a fitting room and reassured her, “That wasn’t that much!”

Cherish the size you are now.

Kondo stepped out of the dressing room in her first item: a jade, graphic-print Tracy Reese shift. In stocking feet, arms crossed to cover a deep V-neck, she asked her husband to retrieve a modesty garment from the intimates section—a seamless beige camisole.

‪She pronounced the dress “probably too small for me right now.” ‪Kondo is expecting her first child this year, but said that she is not worried about how her body might change in the future. “I will only purchase what fits me. If I want to lose weight, I do that first, and then go shopping.”

If an item sparks joy, do not wait for it to go on sale.

Passing a sale rack, Kondo insisted the selection of clothing is better at the beginning of a season. “In my case, my size is so small that if I want it but don’t buy it, I might miss the opportunity.”

Reduce until you reach the point where something clicks.

Of ten dresses, Kondo selected two: a gauzy cotton dip-dyed blue tunic dress by Holding Horses in size extra-small petite, and a buttercup-yellow brocaded sheath dress by Tracy Reese in size 2. The posy dress was cute, she said, “but I do not really have to have it.” She handed them to her husband, who paid at the register and returned with an appropriately on-brand white paper bag. With an oversized trench coat draped over her shoulders, Kondo stepped out onto West Fiftieth Street, vibrant and happy, looking full of joy.