We have a 55 gallon "fish tank" with a screen top. The heat lamp is in the middle with maybe 1/2 inch extra cut out of the tin foil. A small (2 inch x 2 inch) square cut out of the tin foil on his cool side. This set up supposedly helps with air flow.
A water dish sits 3/4 of the way under the heat lamp. His warm hide is right next to that water dish. Then I bought sphagnum moss from the pet store and soaked it (squeezed out excess water) and stuck it into small disposable cups. I had 4 in his tank, two by the warm hid (near the heat lamp) and two by the cold hide. The cups look like the Dixie brand cups but are all plastic. Think clear miniature "red solo cups". Found them at Walmart by the trash bags and disposable silverware. The moss stayed damp for about 3-4 days once the humidity got up to 60 or so. Hope this helps. Loading pics on this website is kind of tricky.