Marks from Wear on a Leather Couch?

I have had good luck with a little olive oil and a soft rag.

We have two large dogs that are like family members---meaning they sit where we sit. I use CPR leather cleaner from Bed, Bath, and Beyond as a regular cleaner for my sofas. It helps clean and brings back the luster to the sofas. One tube will do both sofas and a chair with ottman (completely) a minimum of two times (depends on how heavy you apply it).