Use a clean, soft microfiber towel. And, to minimize scratches, always use some sort of cleaning liquid. A dry MF towel is always more likely to scratch than one that has a liquid to lubricate. I personally like using Chemical Guys Inner Clean all purpose interior cleaner. It works really well on the screen and on the piano console. I keep a small bottle of it and a MF towel in the well of the my door. Plus it smells like pina colada!