Is he outside or inside? Everyone uses something different. I use a mix of soil, peat moss, and some Forest Floor by Zoo Med. On top of that lots of leaf litter. I don't use hides inside because they just dig under in the leaf litter. This is inside for the winter for the little guys. I put some frog moss around the water dish so it stays clean, and lots of plants to hold in the humidity.
Outside I have soil with plenty of plants to hide a small stream with a little pond at the end of it, and lots of leaf litter on one end to dig under, and a cave made from slate with leaf litter inside it. Hope this helps.

outside: