What you will need:
Old crayons in different colors
Some kind of mold (Candy mold that you ONLY use for this, or I used a minnie muffin tin with minnie cupcake liners)
Oven (Ok I feel silly saying this but ovens are for adult use only! ;) )
First unwrap the crayons and break them into little pieces. This is a good thing for the kids to do. Just make sure they are small enough to fit in the liners.
Set them in the lined paper cups....
We set the oven to 175 so the crayons wouldn't boil. Ewww my oven needs cleaned! Leave them in there until they are melted. Ours took about 5-10 minutes. When you take them out be careful as you don't want hot wax all over you. I stirred them with a toothpick so the colors were swirled.
Let them cool and pop em out...viola!
We made these for a friend's son who just had a baby sister. These would make wonderful party favors, or would be great to stick on some homemade Valentine cards. Here are instructions for Zakka life on how to do it with a mold. Also weefolkart has a wonderful tutorial on how to make soy crayons but their site seems to be down right now. I will put a link up as soon as their site is running :)