I overcast the raw edges before washing.
I use either a long narrow zig-zag stitch or a narrow overcasting with the serger. My serger is my first choice, but if I have black on it and the fabrics are light colored, I go with the sewing machine. It's easier to change the thread colors on.
Takes a bit longer, but then the most fabric I ever lose is the width of the stitching - and no loose threads to fight with.
I find that many fabrics shrink some and I prefer a flat quilt.
You will notice that there seems to be no definitive "right" answer to this question.