I also use a glass tank. I also have had serious issues with keeping humidity up. I was resorting to spraying the take daily just to keep the humidity above %40. I added foil to the top 9/10 of the lid and that helped, but i was still having to spry things down every couple days to get the humidity up.
I tried putting some sphagnum moss in the tank and it has helped tremendously. I rarely have to do much to maintain the humidity at 55-65%. I also tossed a small (loose ping-pong ball sized) hunk into his hide.
I have never had a problem shedding. (3 one piece sheds :gj: )
http://ball-pythons.net/gallery/file...0612_thumb.jpg
He seems to be happy with it. :D