You place a pretty leaf or flower on a blown egg, cover it with a piece of stocking and secure it with a rubber band so that the leaf is pressed flat against the egg. I then suck some water into the egg so it doesn't float. Boil with onion skins for several minutes and you have a lovely brown egg with a leaf pattern on it. I rubbed the shells with olive oil to make them shiny but I'm thinking of washing it off and using spray lacquer instead.
Onion Eggs at Crafster