Use plastic skate guards when walking around in your skates off the ice. Even a small amount of dirt can damage the fine edges on your blades.
After skating, take the time to dry your blades with a cloth and protect them with padded blade covers. Do not leave plastic skate guards on your blades after skating, as even a small amount of moisture can cause blades to rust.
Use leather waterproofing on your skates as recommended by the skate manufacturer. Very wet or very dry leather will break down and your skates won’t last very long.