What's the best cloth to clean the DS screens?

I have a Memorex Mincrofiber cloth that i got from amazon but i am not sure about it. I don't now if it is me or what but almost every shiny thing i have cleaned with it have at least a minor scratch on it. Can some microfiber cloths cause scratches? Wich ones are the best?

I got these and they work just fine.

http://www.bestbuy.com/site/Dynex%26%23153%3B+-+10%22+Microfiber+Cleaning+Cloth/9302113.p?id=1218081090509&skuId=9302113&st=microfiber%20cloth&cp=1&lp=2

I use a glasses cleaning cloth for my DSL. Works pretty well and I have noticed any scratches.

I also use a sunglass cleaner cloth but, for anyone that uses a cloth to clean their stuff, shake the cloth violently to get any debris off (it causes scratches) and breath on whatever you are about to clean so it fogs up, it helps somehow with the debris on the screen I think.