I've been prewashing my fabric for years, many, many years; and I have found that I get fewer tangles when I cut the corners off each piece of fabric. Yes, there may be some that get tangles, but when I take them out of the dryer, I just trim them off. It was much easier when we had our own washer/dryer, but now that we're living in an apt., I do a lot of prewashing in my bathroom sink, then hang them over the safety bars in the tub. I like to iron them when they are not quite dry, but it doesn't always work that way, then I spritz the fabric with plain water. Prewashing this way I have discovered fabrics that bleed, ones I hadn't expected to bleed, so I'm glad I prewash.