I simply use a 8 oz styrofoam glass ou plastic glass and make a hole in the bottom with a pin. I let the water fall on their hiding spot or plant so it platters around a bit. I do this about 3-4 times a week.
I have about 3 inches of soil in there and I try to allways have about 2 inches of soil that stays humid all the time.
A good trick is to put a plant in there, she'll tell you when your soil is not humid enough.
good luck
WYZ