I got this idea from a friend of mine. She makes heart-shaped crayons for her kids every year for Valentine's Day. It is so easy to melt down all of your old and broken crayons to make new and beautiful ones.
First, find all of your old and broken crayons and take the papers off. You can soak them in some cold water for a few minutes and the papers will come off fairly easily. Crayola brand crayons melt the best.
There are two different methods for making your crayons:
The double boiler method: melt the crayons and pour them into fun-shaped ice cube trays. You can find so many fun shapes at the dollar store or thrift stores. There is no reason to spend a lot of money. I also borrowed from friends. You do need to know that you can't use the molds for ice or food after you have made crayons, it leaves a waxy residue.
Brake your crayons into small pieces and put each color into its own clean tin or aluminum can. Boil some water in a shallow pot then turn it down to low. You only want about an inch of water in the pot. Put the cans in the pot standing up. Watch them to make sure the can don't fall over. You might want to swirl the cans once in a while to help melt your crayons. Once the crayons have melted, use an oven mitt to pick up the can and pour the crayons into your molds. The cans aren't very hot but the wax inside is. Let the molds sit for a while so the wax can harden. Pop them out and enjoy your fun crayons.
The baking method: using a silicone baking mold. There are a lot of fun baking molds out there but they are more expensive than ice cube trays. Remember, you can't use the mold for food after making crayons in it so look at the thrift store to find cheap molds. This method is easier than the double boiler method. Preheat your oven to 250 F. Fill your mold with crayons pieces (different colors make for really colorfull crayons). Place your mold on a baking sheet incase the wax drips. Bake for 10 to 15 minutes until wax is melted. Remove the mold from the oven using an oven mitt. Let the mold sit and cool and the wax harden. Pop them out and smooth any rough edges.