I've always had good luck with Lexol leather conditioner, and Lexol leather cleaner. I use the cleaner twice a year, and the conditioner every three months or so. I apply both with a terry applicator. Just my technique. You can see from the photo below Lexol leaves a nice matte finish.
Great forum. Nothing better than a spotless car. I've been detailing my own cars since I was a teenager, and look forward to learning some new tips and tricks. My cars are 07 997 Turbo (basalt black) and 09 Cayenne GTS (Black). Happy polishing.