In the Midwest, fashion and jewelry trends take time to catch on. This can make merchandising challenging—especially for a luxury jewelry retailer who travels the international jewelry and watch circuit ingesting every next-best-thing seasons before it hits shelves.Cathy Tivol, the third-generation owner of Tivol fine jewelry stores, has grown the business her grand­father Charles Tivol founded in 1910 to encompass two massive 6,000-square-foot locations—in Kansas City, Mo., and Overland Park, Kan.—by consistently mining the sweet spot between stylishness and timelessness for her loyal clientele.The stores feature a panoply of top luxury brands: Rolex, David Yurman, Patek Philippe, H.Stern, Forevermark, and Cartier, among them. But Tivol also caters to young and style-minded buyers with cool, well-priced collections including Shinola and Marco Bicego.“We try to get the best line