I am a big fan of Duragloss products. For the seats, I usually use a deep rub in cream 4-5 rimes a year, but on a weekly basis I wipe the seats down with Duragloss Leather and Vinyl Dressing:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
What a lot of people overlook is the wear and tear to the side bolsters getting in and out of the car. Overtime, the side bolster rips and frays and generally ages much faster than the rest of the seat. I use the dressing purely to create some lube so I slide in and out which removes stress on the leather.