Clean the leather by starting off with a simple vacuuming to get all of the unwanted dirt and grime out of cracks and crevices that form in leather. Vacuum the piece of leather as you would vacuum anything else, making sure to get all of the dirt and dust out of every crack in the leather.
Determine how color from the manufacturer was applied to your leather. Leather is typically either aniline-dyed or pigmented. This is an important step to renewing your leather, as some leather cleaners will tend to take the color out of the leather. You can determine if your leather is aniline-dyed or pigmented by placing a drop of water in an unseen location to see if it soaks in. If it does soak in, your leather is aniline-dyed. If it doesn't, chances are your leather is pigmented and slightly water-resistant. Since color is essentially painted on to pigmented leather, using solvents may take the the color off when cleaning, so be sure to be careful and test clean in an unseen location first.
Wipe the leather periodically with a soft, white cloth dampened with water. Old or unused sheets and pillowcases work great for this if they are clean. This will help to pull off dirt that seeps into cracks and crevices that the vacuum might not suck up. This is especially effective for pigmented leather where the color is painted on, but isn't as effective for aniline-dyed leather surfaces. For aniline-dyed leather, regular vacuuming is essential in maintaining a clean surface area.
Clean the leather using solutions made specifically for leather surfaces. Once you have the majority of the surface dirt off the leather, you can proceed to getting a deep cleaning and conditioning of your leather. Leather cleaners and conditioners can be found at any supermarket or even auto shops, as leather is used frequently in automobiles as well. For both pigmented and aniline-dyed leather, cleaning and conditioning at least once a year is highly recommended to maintain your leather's luster. A good leather solvent should be pH balanced and glycerin-rich. Follow the directions on the cleaner by spraying a softened cloth and applying it to the leather one section at a time, then wiping it clean with a different cloth.
Apply the leather conditioner. Conditioner works as a preservative and helps to soften the leather and prevent it from cracking. You can apply the conditioner in the same way as the cleaner. Apply a few sprays to a clean cloth or sponge and wipe it onto the leather's entire surface. Let the conditioner soak in for at least a few minutes, and then wipe off the excess with a clean, dry cloth. The conditioner uses fine tanning oils that bond with the leather's fibers to nourish it without leaving it greasy. This will bring back luster to your leather and keep it strong and supple for years to come.