I pre-wash everything; smaller pieces I wash and rinse by hand, machine spin in a garment bag and hang to dry. I used to zig zag fabric edges before washing, but now I notch the edges in a couple of places instead. This doesn't prevent all of the fraying, but it controls it somewhat. I add a small amount of Woolite liquid to the load and dry on a delicate setting (just because that setting works better on our dryer). I always lay out the fabric somewhere for a while, in case it is not completely dry. I snip off the worst frays and hand press and fold the fabric until I'm ready to use it.