Recently I have been experimenting with a very dark Canadian clay.  I apply a white slip and then press botanicals into the clay to create an impression then use water abrasion to raise the impressed leave from the surface of the clay.  Using a thicker version of the slip colored with ceramic stains, I finish selected areas of the piece with a rough texture. It is really combining techniques used for the Porcelain Intaglio and the Modern Botanical work.