Designers known for women's scarves are putting their prints on men's pocket squares. Below, a yellow one with hearts (Salvatore Ferragamo; $70 at Bloomingdale's), Pucci's pretty shapes ($68; Bloomingdale's) and Gucci butterflies on a brown background ($90; Saks Fifth Avenue). How do you wear them? Stylists say dump the tie or wear a plain color that brings out the hankie. But stay away from stripes. To tone down the effect, look for a square with smaller patterns and tuck more of it in (see folding guide, below). Women can play along, too. Bloomingdale's reports some female shoppers are buying them to tie on their wrists and purses. How's that for pocket change?