My requirements are still low so I use a mix of repti bark and forest earth (both made by exo terra). Not really practical if I had a dozen herps but since I only have one I can spoil her. I find the mix holds moisture really well, when she is in bue phase I mist it twice a day to keep humidity up, other than that I just place a large water bowl in the middle of the cage.
Common sense, the least common of all senses
0.1 BCI 2.2 balls