When you think "luxury," images of diamonds, jewelry, furs, high-fashion gowns, designer shoes and bespoke handbags likely come to mind. Fashion and lifestyle magazines are crammed with ads showing women sporting these and other high-priced items.

You might be surprised to learn, then, that according to a new study from Epsilon and The Luxury Institute, the majority of luxury spenders are men. Perhaps not for much longer, though. The number of affluent women is on the rise, and they have their own ideas about wealth and luxury.

Women's economic power has been growing since the recession, despite overall wage and income stagnation. Merrill Lynch reports the number of U.S. women with six-figure incomes is rising at more than three times the rate of men who earn that much, according to the Census Bureau.

Women now command $5 trillion in purchasing power, and 43 percent of the wealthiest Americans are women. Nielsen predicts that by 2028 women as a group will be earning more than men.

And who are these women? They are professionals, business owners, executives and politicians. According to a study by the Spectrem Group, 93 percent of high-income women are college graduates, and 63 percent have an advanced degree. They are less likely to be married or have children or grandchildren than are less-affluent women.

The majority have an annual household income of $200,000 or more if single, and $400,000 or more if married. Analysis of Federal Reserve data by the Luxury Institute found that households earning at least $200,000 with a minimum $5 million net worth grew 19 percent to 1.8 million between 2010 and 2013. High income women helped to drive that growth.

Trend watchers JWT Intelligence chose "Womenomic Luxury" for their "Future 100" list of top market trends in 2015. They noted that luxury brands Gucci and Hermès have already staged special events celebrating the power of women.

"As more women hit the affluent, high-net-worth and ultra-high-net-worth brackets, luxury brands that traditionally have catered to men will have to find new voices, products and approaches to speak to a growing category of sophisticated, affluent women," the authors observed.

These women place a higher value on quality of design and craftsmanship than on glitz and glamour. They spend time researching before buying, and they expect the representatives they deal with to be experts on their products and services.

The Spectrem Group, for example, found that affluent women were substantially less satisfied with their financial advisors than were other clients because they felt the advisors were less knowledgeable than they were and did not conduct themselves as experts.

A survey of affluent adults conducted by Shullman Research found that women think about luxury differently from men. When asked to describe luxury in their own words, both men and women mentioned "quality" and "expensive."

Words women used that men did not included "premium," "best," "fine" and "designer" — emphasizing attention to craft and expertise. Men, on the other hand, were more likely to choose words that connote status, such as "classy," "fancy," "rich" and "top-of-the-line."

Interior designers looking to attract high-income women as clients would do well to heed the results of the Spectrem survey on what would cause them to change their financial advisor. Poor communication skills ranked high, but what set these women apart from other investors was their dissatisfaction with the investment returns.

If the financial advisor was going to charge them as an expert, they expected the returns to be better than what they could achieve themselves. They also felt advisors did not understand their tolerance for risk, even though they had discussed it together.

The takeaways: Be professional, demonstrate expertise and exceptional value, listen first, show your clients you've heard what they've said, and recognize their knowledge. Establish a dialogue and lay the foundation for mutual respect, and you'll have the beginnings of a productive relationship.