There’s been a lot of change in the beauty industry since Diane Miles stepped off a plane from London arriving in the US some 13 years ago to serve as marketing director for luxury brand Christian Dior.

Just think of the retail landscape alone.

“I was surprised by how department stores dominated the prestige beauty industry, but how limited the shopping experience was,” she told Happi in a phone interview last month.

Today, prestige beauty retail has changed significantly. Sure, women still visit the department store counter, but in 2014, they are just as likely to shop from the comfort of their couches thanks to QVC and HSN, on their laptops and mobile devices, and in open-sell environments like Sephora.

Miles, who has more than 25 years of experience in building skin care and cosmetic brands, has been at the helm of many companies that have made their mark in the beauty sector. Today she is an operating partner at investment firm TSG Consumer Partners. She serves as an advisor to the beauty brands in TSG’s portfolio—Alterna, IT Cosmetics, Kenra and Sexy Hair, among others.

The Miles’ resume also includes serving as CEO of Perricone MD (another TSG investment) and Benefit Cosmetics, and president of Bare Escentuals.

“All three of these brands have taught me how to grow a beauty business fast and gain market share,” said Miles. “When working with private equity, like at Perricone and Bare Escentuals, it is extremely important to focus on both the top and bottom lines. Many organizations, particularly larger ones, prioritize gaining market share, but when working in private equity, it is essential to also focus on profit and cash flow.”

According to Miles, there are two key aspects to success in the beauty business: building a great team and placing an emphasis on product development and innovation.

“You need to have the right people beside you, and in an increasingly competitive industry, you can never spend enough time on innovation,” she said.

Miles—who pointed to R&D-driven advances like gel formulations in color cosmetics and the evolution of silicone technology in hair care—places a premium on innovation.

“In beauty in particular, my experience has been unless you can innovate with 15-20% of business coming from new technology or new launches, it is very easy to lose market share.”

The British native suggests that companies get behind hero SKUs.

“Focus on one big idea or one big product,” she said. “That big idea will be your differentiator.”

But according to Miles, “many start-ups or beauty leaders don’t think about their point of differentiation, and in a very crowded environment it is critical to stand out. Think about what makes your product different: is it how you market it? The product itself? The channel in which it is sold? Find out and use it to answer the age-old question: why should consumers buy it?”

This is an issue even in the hottest sector of the beauty world: anti-aging.

“There are so many different products all claiming the same thing. The fragmentation of the anti-aging market is making it almost impossible for consumers to wade through,” according to Miles, who sees an opportunity for a smart company that can “demystify” the cluttered category.

“There is room for a company who can attack that in a simple way that is really credible,” she said.

For Miles, success in the beauty business comes from more than sound strategy alone.

“My biggest lesson has been that it is not just about strategy, it’s also about execution and it is necessary to balance both,” she said. “Many CEOs are great strategists but they don’t spend enough time making sure execution is impeccable. I’ve strived to place equal emphasis on both.”