We dug out all our broken pieces of crayons we've accumulated over the years, sorted them by color, and placed them into tin cans we had been collecting. We placed the cans on top of a cookie sheet and in the oven at 250 degrees and baked them until the crayons were melted thoroughly.
I used craft sticks to stir each color before pouring them into the molds. The melted crayons dried on the stick, so the girls used the craft sticks to color with.
We carefully, using a hot mitt that wouldn't slip, poured the melted crayons into the molds one color at a time.
It's best to keep the tins in the oven until the melted crayons are going to be poured into the molds. It's also best to pour each color after the previous color has cooled for more even layers. When we poured colors over other layers that hadn't cooled off yet, we got a neat marbled look on some layers and a blob of hot mess for other layers.
Overall we were pretty pleased with the end result. We only had large pumpkin molds, but I think I'd like the molds with the smaller shapes better.
This is something we will definitely do again. It's a quick and fun project.