You can't beat this piñata with a stick -- nor should you! Instead, kids take turns pulling strips of "caution" tape from its base. Pick the right one, and a trapdoor releases a cascade of candy.
Using a string, pencil, and pushpin as a simple compass, draw a cone pattern on a sheet of poster board as shown below. Cut it out.
To form the cone, overlap and glue the edges of the poster board, using masking tape to hold it together until the glue dries, about an hour.
Cut the other piece of poster board into an 18-inch square. Turn it wrong side up and glue the 12-inch cardboard square to the center. Fold the extra poster board over the edges of the cardboard and glue it down. Once it's dry, turn the square covered side up and use a craft knife to cut a 6-inch trapdoor through both layers.
Make ten 2-inch slits in the base, most of them in the door. Feed a piece of "caution" tape through each slit, leaving about an inch of tape on the uncovered side of the base. Choose one strip and secure its end to the trapdoor with duct tape. Leave the remaining strips unsecured.
Apply a generous amount of tacky glue to the bottom edge of the cone, then press it firmly to the unfinished side of the base. Let it dry.
Place candy in the Piñata (not too much, or the trapdoor won't stay closed), then close the trapdoor. To hang the Piñata, thread a bit of twine through holes in the top of the cone (we reinforced ours with stickers) and tie it to a branch or archway.