Aquariums and large plastic sweater boxes work best. Aquariums need to be covered with a glass top that has been raised a fraction of an inch to allow air circulation. The sweater boxes usually need no modification unless the lid appears to fit too tightly. A few small holes should then be drilled though it. The top helps keep the humidity high and the salamanders in.
Most small salamanders can climb glass and plastic with ease.
Soil is not recommended. Gravel does not hold moisture as well as wood rot and extra care must be taken that it does not dry out. Even a few hours of too low a humidity will kill lungless salamanders. Sheet moss, wood, or flat stones should be provided for hiding places. A water dish should be made available for most salamanders.