Here's a quick fun project! You don't need to be able to draw more than a doodle, and you end up with pretty & interesting jewelry!
These charms can be used for earrings, necklaces, or whatever you'd like. They are made out of plastic recycled from a to-go container (#6 plastic). The directions below are for 2 matching ones, which could be earrings. Because plastics & pens vary, you might start out with a test piece so see how much your plastic will shrink, and how your colors come out. Or just jump right in! It's only trash.
If you want more ideas and info, I did a whole bunch of experiments on my blog
EDIT: and I did a Christmas ornament tutorial here: Santa Shrinky Ornaments
This was the first project I tried, and I've updated the instructions based on what I learned on the best techniques.