Start with a clean egg and using a paper piercer or similar tool (a thumbtack with the little handle is a pretty good option!) gently press the sharp, pointy tip into one of the ends of the egg and make a hole that is a little bigger than the size of a pinhead.
Next, repeat by poking a similarly sized hole on the other side. Use a corsage pin (the longer ones with the beads on the end) to swirl and scramble the contents of the egg. The yolk won't be able to pass through a hole if it is intact, so breaking it up is very important.
Wipe off one of the ends, gently hold the egg to your mouth and carefully blow the contents of the egg into a container.
Keep going until the egg shell is completely empty.
Carefully rinse the shell in water and then dry. It is now ready for use!