Would you care to share how you make them? I know nothing about shrinking plastic and I'd love to know how it's done!
Sure, but i don't have anything that I do that's unusual, I don't think. Basically, I do a drawing from a photo or a friend's dog, or whatever, and then I trace that drawing onto the shrink plastic, using the finest tip sharpee I can find. A couple of tips that do help me--when you bake them, use a piece of chipboard (or just the cardboard back of a legal pad) as your tray. I also let the chipboard warm up with the oven (350), so that it's already warm when you put the plastic in (rough side up). All of this should keep your pieces from sticking to the tray, and should ensure that they come out flat as a pancake.
If you have an embossing heat tool, then you've got more options. If you have spots on the shiny side, you can heat it up to smooth it out. Or, you can heat the plastic (already cooked) and then press a stamp into it, for an intaglio look (like in this zebra pendant).
And you can also use the heat tool to shape the pieces, if you want a domed effect or something like that--just put it on top of the shape you want (like a wooden ball) and heat it until it slumps into shape.
And that's about it! ) Let me know if anything doesn't make sense.