There are a lot of leather care products on the market, probably too many. I've been using Lexol for many years and will continue. Is Lexol the best, I don't know, it was recommended to me years ago by a friend that restores classics. I'll stay with it since I have no reason to change. Lexol keeps my leather soft and oiled. I use the Lexol leather cleaner (not the spray) and a good-quality horsehair brush to clean the leather. I follow the cleaning with the Lexol conditioner (not the spray).
I keep after my interior with a damp microfiber cloth. If it needs more, then I use a little bit of Murphy's oil soap with warm water.
I'm interested to see what others use on leather seating and dash/trim.