Here's the step by step:
Carefully spread the podgeable with paper clay.
It's best to add color to these with some sort of spray. Oh, and you can poke a hole at the bottom when the clay is still wet, if you wish to add beads hanging down from your brooch.
After you've added color, let it dry some, and then go over the edges with a pigment ink based ink pad. Then, just spray it with some acrylic sealer.
And that is indeed that! I hope you enjoyed my little tutorial!