most clothes work "ok" but can discolore the screen over time (only use lint free ones if you can). a slightly damp cloth is generally fine, just dont press too hard and dont use too much water so it then leaves water marks everywhere. By "stuff" I am assuming you mean dirty/sticky marks and not simply finger prints or dust, since they can both be removed with a dry cloth, which as long as it doesnt scratch the screen is allways fine (afaik).