“Whether in the boardroom or a cocktail party in the Hamptons, always keep it preppy and cool,” says designer Tommy Hilfiger. “Pairing a gingham shirt and tie with a solid navy suit allows the shirt to pop in just the right way.” Thomas Pink executive Simon Maloney says: “Gingham shirts work well with a variety of tie styles—straight ties, bow ties, skinny and knit ties. Feel free to experiment.” Tommy Hilfiger shirt, $68; tommy.com. J. Crew tie, $60; jcrew.com.