My daughter enjoys opening her lunch and seeing a new shape to her jelly sandwich everyday. This week, I've put the same one in everyday. I use a hand shaped cookie cutter, then I cut the shape of a heart on top with a knife to look like the hand from the book Kissing Hand by Audrey Penn. Both of my children have been read the book since preschool. I would put one in my son's lunch, but he doesn't like sandwiches; just soup and it's a little hard to shape that into anything very fun. : )
I wanted to share this with you because I was pretty proud of myself for coming up with something she loves and she knows exactly what it means when she sees it. Maybe your children will like it too if you decide to try it. If you haven't read the book yet, I would recommend getting a copy at the library. We bought one through the Scholastic Book Fair for like $3.99 or something -- very reasonable for a book with lots of meaning for little ones!