Leather is an expensive, upscale option in most cars so caring for it is essential. There are two vital facets to leather care: cleaning and conditioning. Cleaning is obvious. Conditioning has to do with the nourishment of the leather: the penetration of product into the pores of the hide. This keeps the leather saturated, moist and resilient. The cleaner the pores, the better the leather will accept conditioners. It should be noted that warm leather surfaces are more receptive to conditioning products because the heat opens the pores of the leather, allowing the conditioner to better penetrate and be absorbed. So working in the heat of the day or firing up the seat warmers will be beneficial.
This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2014/08/29/leather-care