4 tsp White Glue (elmers works well)
2 tsp vinegar
various pictures (cut from wrapping paper, cards, computer printouts, etc)
Blend well and then brush onto the backs of pictures. Allow to dry completely before using stickers.
To use: brush lightly with water, (we don't recommend licking them) and stick them where desired.

Liss Notes: One idea is to cut various facial features out of construction paper & make stickers out of them. The kids love to create funny faces with the pieces they've designed.
To Clean up: wash any remaining residue with baking soda/water mix..