* A trinity shamrock. We always make some sort of shamrock while I tell my children how St. Patrick explained the trinity to the Irish: God is one, but three, just as the shamrock is one leaf with three parts. Click here for more details
* Eat green food. Every meal must have some! As a snack, we like these green mint chocolate chip cookies.
* Talk about snakes. Legend has it St. Patrick banished them from Ireland - but scientists doubt there ever were snakes on the Island. Probably, the story is figurative, meaning Patrick got rid of pagan religions in Ireland. Try this uber easy pipe cleaner snake craft.
* For silly fun, be leprechauns. These beards are easy to make and always give the kids giggle fits. Also, just for fun, we sometimes make shamrock hats from paper plates.
* Read some St. Patty's day books, like these. It's shockingly difficult to find children's books about St. Patrick that suit most protestant families; my favorite is the board book The Story of St. Patrick's Day. It does a good job of explaining why we celebrate this man of God. If your kids are 8 or up, you might just want to find some reading material online, like this, from the History Channel, or this, from Catholic Online.
Again, I try to focus the kids on Patrick's calling from God, the fact that he ended up serving those who originally enslaved him, and that he brought Christ to a place that knew nothing of him. Cuz that's what St. Patrick's Day is really about.