Turning eyeshadow kits into watercolor kits. Just did this with a couple of old compacts I wasn't using. *Update* I have found that the super inexpensive watercolors crack and break causing a lot of messiness. Do with that info what you will.
Tissue paper is no longer just for stuffing gift bags. Use tissue paper in a lot of art and paper projects because it is so versatile. It's flexible, semi transparent, thin and printable. See how to print on tissue paper: