Piping Christmas crackers is a great way to use up that last bit of stiff consistency royal icing in any festive color; don't worry, you don't need to pipe a tiny hat, toy and joke to go inside them. You'll need round tip #12, petal tip #101, a flower nail, a Styrofoam block to rest the nail in, a glue stick, an offset spatula, parchment paper squares, and a dusting pouch filled with a 50/50 mix of cornstarch and powdered sugar. Start by sticking a parchment square to the flower nail with a dab from the glue stick.
You should be left with a reasonably tidy cylinder. Neaten it with a fingertip you've touched to the dusting pouch, if need be. Allow it to firm up for a few minutes.
Switch to the #101 tip to pipe the ruffly ends. Hold the narrow end of the tip outwards and pulse the tip back and forth to form ruffles while piping in a fanlike motion. These could work for any holiday if you adapt the colors thematically.