I revived a pair of WWII boots with neatsfoot oil, then conditioner.
Depends on the sort of leather. My Docs just get misted with a liquid saddle soap that's rubbed in with a rag, takes off the dirt and keeps them soft.
Here, you need to get winter salt off boots, it'll kill the leather quick.
Finally, if you go to a store like Agway, Tractor Supply or such, you will pay 1/4th the price in the saddle area for stuff as you will at places like Cabela's. Usually a giant container for the same price as a tiny tin!
(It was a major blow to migratory ma__holes when they canceled a Starbucks down the street and built a Tractor Supply Co....I was overjoyed. Gun safes and leather goods and tools. That's what NH needed more of, for real!) :)