For Green Salamanders, I use 12x12x18” Exo Terras for breeding pairs and raising groups of juveniles. I keep them with a nice stable stack of sandstone with ~1/8-1/4” crevices between and some vertical slabs of oak bark. Bark from oak firewood or logs (baked in oven to sterilize) is probably better than cork as it is thinner and you can squeeze it into tanks easier. I cover about 3/4 of the screen top with plastic and use a single ~3W led to light it. This is enough light to grow moss and ferns on the rock.
Thoroughly check over your enclosure for any gaps...if it is big enough for a fruit fly to escape I'd say seal it up with silicone. They can squeeze through extremely small openings.
I have an RO drip that turns on for 30 min/day, and route it such that it runs down one side of the rock pile and the other side stays drier to give them a gradient to choose from. I use a bit of organic substrate on the false floor not covered by rock (mix of coconut fiber, pine bark, sphagnum, oak leaves), and a little on the rock pile to wick the moisture around and root the ferns. The false floor is over an open bulkhead drain such that no water is actually pooling in the tank. In addition to the RO drip, I spray down the tank around once/week.
Temps from 60-70F are fine, though they can handle down into the 40s or up into the mid 70s with no problem.
I feed mainly appropriately sized crickets and fruit flies to all ages, dusted with Repashy Calcium Plus and crickets gut loaded with Repashy SuperPig.