I have two different Wilton books that feature the chrysanthemum--and each one shows how to pipe it a completely different way: from bottom to top (in the more modern book) and from top to bottom in the old-school book. I encourage you to try both ways to see which you prefer. You'll need a piping bag fitted with a round tip #5 and filled with any color stiff consistency royal icing, a flower nail, a parchment paper square for each mum, and a Styrofoam block. Start by sticking a parchment square to the flower nail with a dab from the glue stick. You'll also need a tip #79 or #80, depending on whether you're using Ateco, Magic Tip or Wilton (this is an Ateco #80). Hold the round tip just above the parchment square and pipe a mound:
Not only is the mum darling in any color, it's now one of my favorite "cupcake flowers"!