Ventilation is the key. Moisture builds up when warm air meets a cold surface with nowhere to go. Gable vents, ridge vents, or even just cracking a window periodically lets air circulate and prevents condensation from forming on the walls and ceiling.
If you're using the building for storage, avoid sealing it up completely. Air needs to move. For a finished interior with insulation and climate control, the insulation itself prevents the temperature differential that causes condensation. Spray foam is particularly effective because it seals gaps and eliminates the cold spots where moisture likes to collect.
