I've had great success with a tupperware container full of damp peat (saphngum) moss sitting under the overhead heating bulb and 3/4 of the screen covered with a t-shirt. Nothing to terribly fancy. The moss needs to be rewetted every 3 or 4 days or it dries out and should be replaced altogether once ever couple of weeks (or however often your climate dictates) so it doesn't mold. Occassionally, like once ever 5 to 7 days I mist the sides. Humidity holds around 60% by doing that. When it comes shed time I'll just add a water bowl over the uth and/or a wet tshirt. Should work like a charm... I hope.