If possible cover as much of the top with foil as possible.
If you have lamp(s) on top, leave just enough room for it/them with an extra 1/4 inch or so for safety and ventilation.
You may have to experiment with bedding.
For instance, Sauzo is a huge proponent of Aspen as is others. I don't care for it for humidity.
I love the bag of fine Eco-earth coconut husk. But first, I lay down a layer of clay balls, which I got at Petsmart. The balls hold much more water and Slowly release it.
Yeah the Coconut is sticky, but that is temporary. It will pack it down in a firm foundation that makes cleanup a breeze and lasts a very long time!
I've never had mold problems like I did with Aspen. Funny thing is, Sauzo says the opposite.
That's why I say you may have to try different stuff out and see what works for you.
Once I went to coconut, my humidity improved drastically. When I added the foil, it was pretty much perfected.
