moonpi...i wash the heck out of my fabrics the minute i bring them into the house. 2x in the hottest water and dryer on the hottest heat. i buy some extra fabric to allow for shrinkage. i don't bother to wash the tops any more after that. i also wash the backing the same way. anything red washes alone. if it bleeds, it's out. i have no time to play with it. as a result, i
hardly use real reds, unless it's part of a print.
i know you're not supposed to use regular wash detergent on quilts, but if i am giving a quilt as a gift i know that people will use detergent, so i begin that way. no bad surprises later. if it is for me or for a wallhanging, i am careful to wash using quilt soap only.
i turn down a narrow bit at the edge of the fabric before washing. i find it's the only reliable way to eliminate fraying. i think it's worth the extra five minutes.