You can typically buff surface scratches that do not penetrate too deeply into the leather with distilled water. To start, apply distilled water one drop at a time to the scratch until you have completely covered the scratch. Do not dampen the leather too heavily or water stains will develop. Use a chamois, which is a soft leather cloth typically made from sheepskin, to buff the dampened scratches away.
Another option for removing light surface scratches from dark leather is to buff them out with olive oil. Carefully add several drops of olive oil to a lint-free or soft microfiber cloth and buff the surface scratches with a back-and-forth motion until the scratches are no longer visible. Do not leave the olive oil on the leather; immediately wipe the oil off the leather with a dry, soft cloth.
If the scratch goes beyond the surface of the leather, it will require more than buffing. You can opt to take the couch to a leather restorer for repair. However, this is an expensive option and you have to lug the leather furniture to and from the restorer’s location. Consider, instead, purchasing a leather-repair kit to fix the scratches. The leather-repair kit works by covering the scratch evenly with a repair compound and letting it dry before smoothing it with a cloth dampened in rubbing alcohol. After the compound dries once again, paint a thin layer of clear coat over the dried compound. Before using any repair kit, read and follow the instructions.
No matter which method you choose, always clean the leather couch after repairing the scratches with an approved leather cleaner and conditioner.
To keep scratches from developing on the leather furniture, keep sharp objects -- such as pet claws, writing instruments and belt buckles -- away from the hide.