Leather is a natural material, it is extremely strong and will last for years if it is cared for.
It is treated in the factory (during the tanning process), so needs less oiling.
It is sensitive to its environment, so will go mouldy if kept in wet area , also will dry out (and fade) if kept in dry and exposed to direct sunlight.
It should be kept supple. Best treated with a natural preservative to both sides. (Only use glycerine-free products due to glycerine may discolours the leather!)
New leather items should be cleaned with a slightly damp sponge and lukewarm water before letting it to dry naturally. Apply natural leather balm or oil sparingly. Over-oiling will swell the leather fibres, which weakens the leather.
Wet leather should never be dried in artificial heat! Leave it to dry at room temperature.