Ask your concrete supplier, home improvement store and local nursery for casting mold suppliers, or search online for companies that sell ready-to-use concrete molds. Materials used to create molds for casting concrete stepping-stones include plastic, metal, rubber, specially-treated paper and ceramic.
Choose molds that feature a center medallion or an engraved picture or are deep enough for you to safely stamp or emboss your pavers with patterns or texture for unique results. Consult your concrete supplier for information about adding color and decorative aggregate material such as crushed glass and about painting and sealing the pavers you make.
Make your own molds from lumber formed into a frame, discarded containers or materials such as urethane rubber that you brush, spray or pour to make molds of an original object-model. Create custom pavers with additions of special objects to your aggregate or by working the finish while wet or after the concrete has cured.