A couple of years ago we were learning about Imperial Russia and the famous Faberge eggs that were created for the czar's family. For fun, we decorated a few plastic eggs with gemstones. It was the first time my boys used low-heat glue guns. They had fun and did really well. Because I was supervising (standing by with burn gel, Band-Aids etc.) I did not decorate any eggs. As we were unpacking our Easter decorations, I found our version of the Faberge eggs and decided to make a few of my own. Of course, the boys joined me, they are all pros now and I was not worried about them using the glue gun. We all had fun and decorated some eggs.
You just need a glue gun, bright colored plastic gemstones and plastic eggs. The only tip I have for you is to use some Play-Doh to help hold your egg. That's it.