Polymer clay is so fun to make little trinkets and buttons and pendants with. It's essentially play-doh you bake to set it and keep it forever. Since it sets up really hard you can make buttons and actually use them in garments! Or you can make little beads and string them on thin elastic for bracelets or necklaces. Kids especially love making them and grow ups with a soft spot for that specific child will love receiving (and wearing) them. So cute.
You have to knead the clay in your hands to warm it up and make it palpable, but once you get it going you can roll it out and cut shapes from cookie cutters or whatever you want really. My favorite thing to do when we make beads is to make patterns or flowers by stacking different colors of clay and rolling them into a log so they're easy to slice and bake (like icebox cookies - thanks for the inspiration, Martha).
Different brands have different baking directions, so follow the direction on your label!