Sculpey Etch n Pearl set.
And if you care anything at all about your working surface, cover it in wax paper.
I select the color that want for the iris of the eyes. Here, I'm using a tan color. I knead and roll it out into a pencil size log. To cut I use an exacto knife. There are special cutting tools for polymer clay but what I work with is so small that an exacto fits the bill very well. After a bit of finger rolling into a ball, I place the bits of clay onto the pyrex dish.
Then I press them into a button shape. Meanwhile I knead black polymer clay and use that special tool to cut the black clay.
Then I press the black irises to finish forming the button. After that, its a matter of the holes. The other end of the tool is a really nice point. I poke through the clay and make sure I get the "ting" sound of the tool hitting the glass plate. If you don't go far enough, you end up with a hole that will close up on the back side. If that happens you can use your exacto blade to ream out the hole after baking.