Controlling Humidity

Whats the best way to keep an average humidity in a large glass tank?
I'm using a paper pulp substrate, an overhead 100w bulb, and flexwatt under the hide.
Everything seems to dry up after a bit, and I don't want to dampen the pulp substrate to much because of bacteria/fungus. Would adding plants, maybe moss work? Whats worked for you guys?

There are a number of tricks you can try, but the first step would be to ditch that bulb. Bulbs tend to dry out the air pretty fast. You could try getting another UTH to place on the other side of the tank, but you may have to invest in another thermostat or at least a rheostat.

Also make sure you cover up most of the top if you're using a screen lid. You can use saran wrap, plexiglass, or even aluminum foil. Another thing you can try is placing a bowl in the tank with soaked paper towels, but you will have to change it a couple times a week to prevent mold or mildew growth.

Keep in mind that Balls don't require a lot of humidity unless they are shedding. A good humid hide might be all that you need. You can construct one pretty easily by cutting a hole in a Tupperware type container and placing moist sphagnum moss inside, or even a damp paper towel.

If I made a damp hide, should I keep supplying a dry hide? Would it replace either the cool or hot hide?

What about adding a good sized piece of moss to the floor of the enclosure?

..and any opinions on misters?