Preheat your oven to 250 degrees Farenheit
Put your cupcake wrappers into your cupcake tin.
Fill the wrappers up with whatever colors you want. (You can make designs - only the wax will melt and shift slightly. Just be prepared if you have a perfectionist in the house.)
Only fill molds up about 3/4 of the way. You don't want the wax to spill over into your oven.
Set your mold or tin over a baking sheet to catch any spills
Place the tin into the oven. Turn your oven light on, and in about 10 minutes, have the kids come and see. Their crayons are melting into a cool design,. Leave the crayons in for about 15-20 minutes.
Set them in a safe place to cool. They cool off pretty fast. I think in about 20-30 minutes, they are ready to peel the wrapper off and use it.
If they are still warm, leave them alone. You don't want tears from using them too early. - I let mine sit overnight.