Take a walk around your yard or neighborhood park and look for the smallest leaves you can find.
Start by placing the face (smooth side) of the leaves facing up on cardboard on either newspaper or old cardboard.
First, place your mold onto a flat surface that you can transport, like a rigid board.
Add the dry concrete mix to the bowl and then add some black powdered pigment.
Turn the mold upside down and then press each concrete coaster out of its cavity and then remove the leaves from inside the concrete.