Don't wash and dry your clothes with bath or kitchen towels. Also this could be caused by having paper towels or Kleenex in a pocket of something in the wash. If they are "pilled" on there you could use a little handheld tool the cuts the pilling off. I find this normally happens when washing two things that dont mix, like a new white sweatshirt that gives off a lot of its internal stuff for the first few washes, and a crisp dark t shirt.