anything little i wash in liquid dishwash fluid and rinse carefully. then i put it in a pot and bring to a boil. then i let it cool. whatever shrinkage is going to happen, happens. to tell the truth, i hardly ever buy anything smaller than 1/4 because of the shrinkage.
anything over 1/4 i sew the cut edges together with a zigzag stitch and wash on delicate-hot. then i dry on regular. the cut edges seem to keep each other from fraying.