Leather can be virtually indestructible if treated properly. With a little bit of care and attention, your new leather will last well into vintage age and your vintage leather will continue to have a long happy life.
The most important things to remember about leather is not to get it soiled, soaked, or let it dry out. Despite the fact that all of these things can be rectified to some extent, it is helpful to not let leather get into such a condition in the first place. Proper storage, cleaning, and conditioning will keep leather looking as good as new no matter how old it is.
Storing leather properly when it is not being used is the most important thing you can do to keep it in its best condition. When leather is stored it should not be in extreme hot or cold, or in excessive dryness or humidity.
Keeping leather clean and conditioned only takes a few minutes, but it will make a big difference in how good it looks. If a leather item lasted 30 years of abuse before getting to you, a little soap and water won't hurt it.
Even leather isn't adverse to stains, especially if it's vintage and lived a previous lifetime before finding its way into your closet. However, you're not required to live with the stains of its past; most leather stains will come out easily with a little soap and water. It is even possible to remove blood, oil, and wax in some cases.
Leather can be stubborn about holding on to odors. You may be able to locate a leather specialist or dry cleaner in your area that can remove the odor, but it won't come cheap. Instead try removing unwanted odors at home. There are many safe and gentle methods of removing odors like using baking soda.
Although leather is very durable, it is not indestructible. Improper care or cleaning can crack and dry leather skin, remove finishes and colors, or make it too stiff to wear. Keeping leather away from chemicals, heat, and humidity are key. If leather is like skin, think of its care as anti-aging; if you wouldn't put it on your own skin, it probably isn't very good for the leather either.