just a regular 40gal glass tank with a mesh top and cypress mulch. but I got one of those ultrasonic fogger/misters things. I think its a little over kill but I couldn't keep the humidity above 30 without it.
try putting that mister on a timer so that it doesn't go off so often. it will be 90 right after it goes on, but then should taper down pretty quickly to the 50's. Like a previous author said, too high humidity leads to bacteria and other problems. honestly, i would suggest getting rid of it altogether and trying to use a larger water dish on the warm side of the enclosure combined with restricting the airflow out the top.