To begin, you'll need blown-out eggs. To blow them yourself, pierce one end of a raw egg with a pin, working over a bowl. Pierce the other end, and use the pin to enlarge the hole slightly and break the yolk. Blow out the insides using an egg-blowing tool or a rubber ear-syringe (available at pharmacies), forcing the contents of the egg out through the larger hole into the bowl. Do not let the liquid touch the shell. Rinse, and let dry.