I love bag toppers. You can take an ordinary bag of popcorn, candies, small lotion, an ornament, anything small enough that you could imagine really and make it special by adding one of these on top. I always just staple mine right on to the bag. Nothing too fancy, but it does the trick. Here is a free download designed by myself for you to enjoy.
It is a 4x6, so you will need to find the 4"x9" baggies. They can be found in craft stores. The reason for this size is that it is so much more affordable to have printed. I just print them out on photo paper.