Unlike other types of puppets, the shadow puppet itself is never seen in performance, only the effect it creates. The performing shadow puppet is not just a single object of wood or cardboard, but a collection of things working together. However clever or beautiful the puppet shape, it's the puppet's combination with light and a screen that makes its magical effect.
Shadow puppet shapes are made to block some or all of the light and cast a shadow. If you are trying for crisp edges on your shadows, it's important to keep the material thin. Good quality, small scissors give clean edges and the curved scissors make cutting round shapes easy. Remember, it is the edges of the puppet shape the audience notices most, so spend extra time making sure they are clean and even.
Simple puppets use just the main control wire, but more complicated puppets may need a second wire to operate a moving part. For most performances, two wires is about all a puppeteer can handle. While the same type of wire will do for both main wire and second wire, the best second wires are old umbrella wires. These have a tiny eyelet in the end and let you attach the wire to the arm, leg, head, etc. with thread.
Digitally speaking, one is using shadows as the main medium and edge quality. Similar to cut paper, various cutting tools can be used to give different edges, from frayed to clean and crisp.
Richard Bradshaw (http://www.bytypuppets.com/main/page_richard_bradshaw_style_shadow_puppetry.html)
Martha Stewart (http://www.marthastewart.com/article/shadow-puppets)
Wayang Kulit (http://www.edwebproject.org/bali/gallery/puppet.html)