I decided yesterday's flip flops really needed an accessory: a sun hat! All you need to pipe sun hats are the same tips and colors from the flip flops (round tips #12 and #3 or #2, and star tip #16), parchment paper squares, and a dusting pouch filled with a 50/50 mix of cornstarch and powdered sugar. Start by piping a flattened ball with the #12 tip; hold the tip just above the surface and perpendicular to the center of a parchment square. Squeeze briefly, and pull the tip away straight up while stopping pressure. Touch a fingertip to the dusting pouch and tap down the peak that will probably form; you'll be left with a relatively flat dot.