Select the type of shell you will cut and carve. Choose from conch, abalone, tiger or other cowry species for your carving material. Look for bullmouth or emperor helmet shells for the finest quality carving. Pick a smooth shell of uniform thickness with good color and no cracks or defects.
Saw the shell into sections with a stationary saw if you're carving a cameo, or saw it in half, or leave it whole for large bas-relief carvings. Cut the shell into smaller pieces, forming round, oval, square or rectangular shapes for cameo carving.
Smooth the shell and remove the rough outer layer with a grinding wheel. Smooth and round the back of the shell with the grinder. Stick the blank shell onto a short stick with shellac or wax for working.
Follow the same procedures for carving a full shell or a cameo. Use a photograph or a drawing done from life for your subject matter. Sketch your design with a sharpened grease pencil onto the shell in preparation for carving.
Remove the differently colored layers of the shell with a dremel to rough out the design. Carve a portrait profile by removing the background color shell, leaving the outline of the face in a contrasting color. Carve the fine details with sharp steel handheld graver tools called bulinos.
Sand your carving with fine grit sand paper or emory cloth for a smooth, shiny finish. Soak the shell in olive oil when you're finished, then thoroughly clean it with soap and water.