I picked up some of the smallest plain terracotta pots from Lowe's. $1.38 apiece. Used a Dremel to grind the drain holes a little larger then put a bevel on both sides to smooth the edges out.Place upside down on top of the substrate and voila. Cheap, easy, and my snake seems to be a fan. Spends most of the day in the one on the cool side with about 30 mins to an hour in the one on the hot side.