When Mark Lawson, turns on The Today Show and sees Emma Stone with a Gucci purse in the crook of her elbow, he knows his team has scored a win. On the way to work, when he sees a woman on the street wearing Akris Punto sportswear, he knows his instincts were right.

“You can’t really turn the buyer in your mind off. That’s the fun of it. I go to a restaurant and half of the fun is just people-watching, seeing their styles, seeing what they wear. It’s important to see what’s relevant right now because we need to get stuff on the floor that will sell right now.”

The original Neiman Marcus location in downtown Dallas is 110 years old, a towering building with an espresso bar, the elegant Zodiac restaurant and seven pristine floors of retail. In a cutthroat, fast-moving industry, no store sticks around that long by slacking off. Mark is one of the buyers who works in the offices there, purchasing designer sportswear. He got his start 23 years ago as a department manager at the Prestonwood Mall location, once a very popular shopping destination.

Today, those shoppers are patrons of the Willow Bend store, and Mark still has a lot of affection for them. His experience on the floor translates easily into his job as a buyer, stocking stores with the best and trendiest. A buyer needs a keen, analytical sense of the market and an innate gut instinct for style that can’t be taught. They need to spot trends before they’re trends and handpick the products most likely to succeed on the floor.

“You get it or you don’t,” Mark summarizes. He gets it, so we’re taking our tips from him.

Change with the times

Twenty years ago, a designer would hypothetically launch a trend on the runway. Then other designers would embrace it, boutiques and high-end stores like Neiman Marcus would stock it, and a season later, it would all trickle down.

Now, however, a runway show is on Vogue.com instantly. Companies like H&M and Forever 21, which—granted—have wide selections of cheap clothing, can hang nearly identical designs on sale racks a week later.

Customers no longer shop season-to-season but day-to-day, and huge sales are generated online. So Mark does the same, attending vendor shows and consulting with other buyers on what they’re seeing.

“It all moves much more quickly than it used to,” Mark says, “which is exciting.”

When he started as a buyer, the executive 9th floor—keycard access only—was rows of offices. Now, the floorplan is open and white with glass walls and a sleek, modern feel. It’s all for the sake of attracting top talent and keeping the energy high.

Keep it just in case

Keeping up with the trends is all part of the excitement.

“It’s cyclical. There’s always going to be a demin phase every three years. Skirts will go up and down, but everything comes full circle. In my own closet, I have suits I bought in the late ‘80s that I wouldn’t wear now. They’re long, boxy, three-button suits, but you never know. I’m keeping them just in case,” he laughs.

The Neiman’s trend book shows a rise in exaggerated statement sleeves, ‘40s floral tea dresses, carwash hemlines, bright neon Dayglo colors, pleated skirts, wide pants and bold shades of red.

Don’t be afraid to dress down

Currently there’s an ever-greater trend toward casual clothing in the workplace.

“Everyone isn’t as serious as they used to be,” Mark says. “If I come in a button-down and suit and tie, I walk in looking like a banker. Like I work for Morgan Stanley.”

Half of the profit from the men’s shoe department comes from sneakers—Gucci sneakers that go for $300-600 a pair. Casual doesn’t necessarily mean cheap; a little bit of attitude is in. It’s reflected on the racks at Neiman Marcus and sure enough, it’s reflected in the offices as well; the dress code used to require suit and tie, but today’s employees stride through the office clad in luxury sneakers and artfully distressed denim.

“Sometimes I’m like, ‘Wow, it’s all about, say, blue this year. How did the designers all know? Are they sharing notes?’ And believe me, they don’t,” Mark says and shrugs. “You want there to be a man behind the curtain. But every designer knows what they want to design. Somehow it all trickles down.”

At the end of the day it’s all about the customer and what they’ll buy—most likely online, which generates 30 percent of Neiman’s business.

Shop for where you are

Each of the 42 Neiman Marcus stores has a unique demographic, location and climate which Mark and the other buyers must think about.

“You don’t shop for San Francisco the way you do for Florida.” Neiman Marcus buyers must make sure that the entire stock is varied and innovative, but tailor their selections to each individual store, down to the sales associates on the floor. NorthPark, for example, is one of the biggest stores and has room for a huge amount of stock. Willow Bend, on the other hand, was built to be a much more intimate experience.

Gravitate toward what you love

“You have to have a passion for the product you’re selling. I gravitate toward things I really love. I think about why this woman is wearing this item, what she needs it for. We want each product to be special,” Mark explains. “We get our stores very much involved, which is a lost art. We’re very cognizant of who our clients are and they have a big impact on the store. Take, let’s say, Mrs. Jones,” he says. “Maybe she’s been a customer for 20 years or maybe she’s a size 10. She might likes dresses more than pantsuits. We want to make sure she’s taken care of, so we’ll have a variety of options in store, not just what’s trending.”

At the end of the day, market analysis can only take you so far in a business based on an art form–Mark Lawson buys based on love and a budget.