Decorate cookies.
Flip Flop Cookies: Prepare decorating bag with tip 3 and full strength white color flow icing; outline cookies. Let dry 15 to 20 minutes.
Using teal icing color, tint ¼ cup full strength color flow icing teal; thin to count of 10. Transfer to parchment bag; set aside.
Thin 1 cup full strength color flow icing to count of 10. Transfer to parchment bag; cut small hole in tip. Flow in cookies.
Cut small hole in teal icing bag. Immediately pipe palm trees on cookies. Using toothpick, drag leaves to form trees. Let dry 8 to 10 hours or overnight.
Sunglasses Cookies: Using rose icing color, tint 1 cup full strength color flow icing rose. Prepare decorating bag with tip 3 and rose color flow icing; outline cookies. Pipe bottom of sunglasses handles; pat smooth. Let dry 15 to 20 minutes.
Thin remaining full strength rose color flow icing to count of 10. Transfer to parchment bag; cut small hole in tip. Flow in cookies. Let dry 15 to 20 minutes.
Thin ½ cup white full strength color flow icing to count of 10. Transfer to parchment bag; cut small hole in tip. Flow in eyeglass area. Let dry 8 to 10 hours or overnight.
Reserve remaining full-strength color flow icing for later step.