2. Dip the pinky side of your fist in green paint (or use a paint brush to paint it).
3. Press it on paper (a window, tile floor, etc. if it's water soluble paint).
4. Dip a finger in the paint and add toes.
There you have your mischievous leprechaun footprint.
image from kraftfoods.com
Then we'd leave a note from the leprechaun in charge (Usually Patrick, Ian or Shawn) about a magic treat we left for the kids in the class. We'd take the Pistachio Jell-O pouches out of the box so it was just a plain white pouch and we'd leave instructions for adding however much milk was needed in the recipe. The next day my mom would pour the Jell-O powder (which is white) into a large bowl, and when the milk was added, it turned green... MAGIC!