Go to Home Depot and the heat tape usually in the back by where the heating stuff is. You will see the foam tubes to cover water pipes and the aluminum flex piping for water heaters and heating ducts, its in this area. Get the heat tape that is 2" wide and like the size of a roll of duct tape. This is the best deal and I find it very versital. You can cut it in half length wise if it is too wide for a certain area. I sometimes cover the whole bottom of the Flexwatt w/the heat tape over-lapping the edge by an inch or so to adhere it to the surface. This way you "reflect" the most heat inward into the enclosure.
Good luck man...its easy. There arent too many rocket scientist's doing this stuff (that I know of!!). Its mostly trial and error, learning from other people and books and a little common sense so you dont hurt the snakes or burn down the house.
Take some pictures if you can and post them.