We do at least two things differently.
First, most of us keep ours in plastic tubs. They hold it so well it ceases to be a problem.
Second, we use belly heat and only use bulbs or Ceramic Heat Emitter bulbs (CHEs) when we need them, because they tend to dry out the air. Of course, bulbs aren't an option if we're in tubs.
So, yeah, switch to belly heat and get rid of the lamps if possible. It's better for ball pythons anyway. Make sure you have a thermostat.
I like Flexwatt tape because it's so much cheaper than the UTHs you find in stores. I got mine from http://www.reptilebasics.com. Get the clips ($5) and have them attach them for you (free). Then there's this thermostat which should do great if you're on a budget. Put the thermostat probe between the Flexwatt or UTH and use your digital thermometer probe (which goes right on the glass under the substrate) to set the thermostat. You want to know the hottest place the snake can get to and any heating element can/will burn your snake unregulated.
You can also cover more of the lid, but I'd really work on getting belly heat. They're just not the type of snake that works best with a lamp.