Gather some leaves and brush on the metal leaf adhesive. 

Place glue on the front side, then stick them to the bottom of the mold.

Let dry about 30 minutes until the glue is tacky.

Arrange your leaves on the inside of the bottom mold, and brush on vegetable oil over the entire surface.

Brush oil on the outside of the top bowl.

Mix up the concrete and pour it over the leaves.

Place the other bowl on top.

Place something heavy on top of the bowls to weigh them down.

Let dry for one hour.

Gently sand down any rough spots at this time.