I use paper towels. The girls also get a nest box, which they dig in sometimes, usually to lay eggs, sometimes just to practice digging I suppose. They spend most of the time climbing, but the girls do like to hide under the paper towels sometimes during the day.

On humidity: Lots of ways to deal with this.

1) mist. great way to do it, just mist once. If your geckos prefer to drink during misting, you're doing this daily once or twice anyways. Mine all use water dishes (and actually have been caught using them) so I don't mist as much when natural humidity is up.

2) humid hides. They will use them. another great option, I like sphagnum moss.

3) humid substrate like bed-a-beast. Not ideal for breeding purposes (makes finding eggs a ton harder than with paper towels and a nest box), and I often worry about bacteria and fungus growth.

4) don't worry too much, and take it easy. Crestie humidity requirements are overstated, and easy to handle. Feel free to dispute this with me, but I think 2x daily misting/drying out 30 minutes later being "standard practice" for dry areas is a testament to humidity tolerance. It's good for them to get some high humidity in to facilitate shedding, which is the most important aspect with regards to humidity and cresties, but you certainly don't need 60-80% 24/7. HOWEVER, with young geckos, especially fast growing hatchlings, yeah it's a good idea to keep humidity up as best you can.

These aren't brazilian rainbow boas, they can tolerate humidity variations from 'ideal', especially the adults.

In addition, I vary my cresties humidity with seasons, along with my temperatures. New Caledonia's 'wet season' is the summer and 'dry season' is the winter. It works out nice because minnesota varies in humidity similarly, so I can keep my misting on the same schedule yearround and provide them with a 'natural yearly humidity cycle'.