Over the past 7 years, I have developed my own "secret" methods to create pieces that use real leaves, and yet allow for glaze and the pottery firing process to alter their appearance. Here are the basic steps in my process and some pictures to lead you through how I create them.
With the leaf in hand, I then apply it to the raw clay. In this instance, I have rolled out a slab of clay to make a circular serving dish. After cutting out the initial circle for the piece, I transfer the slab of clay to my work table and visualize the finished piece. Then apply the leaf to the raw clay and use a pony roller to impress it. I let the leaf set up for a while so that when I go to remove the leaf, the clay underneath has had a chance to dry.