I second the cypress and damp towels. I have a 40 gal breeder tank that has cypress mulch, I never need to mist. I have a CHE on one side (regulated with a thermostat) and a nighttime bulb on a dimmer on the other. I put warm damp towels over the middle part of the screen, then cover everything except where the lights are with foil. This keeps my humidity between 50-65 at all times. I usually only have to re-dampen the towels once a day to every other day depending on the weather. I only offer a humid hide when he goes into shed, but so far he has never used it. I also have a large water bowl under the CHE and a small one under the light, so that helps too.
It took a good two weeks to get everything set up and stable, took a lot of tweaking light placement and foil coverage.