The puff fold is best with a patterned pocket square, especially with a double printed fabric because it allows you to see the print on both sides. It works well with both silk and cotton fabrics.
Step 1: Lay the pocket square fully open on a flat surface. Using the tips of your fingers, gather the square loosely in the middle and pull it up with corners hanging.
Step 2: Wrap you hand around the ends and fold the fabric in two so the pully middle and the pointy corners meet and lay against each other.
Step 3: Place the folded end into your breast pocket so the puff and corners show two or three inches. It doesn't have to be perfectly symmetrical, in fact the charm of the puff fold is that it's always different.