I pre-wash all fabrics in warm water, because I prefer working with clean (chemical-free) fabric, and because I don't like the idea of fabric shrinking unevenly after it's been sewn together; that seems potentially problematic to me. I don't pre-test my fabric for bleeding, though I think that's a good idea. I do group my fabrics for color when pre-washing, and use a color catcher for most loads (and they do often come out with quite a bit of color in them.) I dry the fabric in the dryer, then hand press and fold for storage. I press the fabric before cutting, using Best Press.