I don't own a serger. I just straight stitch along the cut edges before I wash the fabric. It helps a lot.
Rodney

Set your washing machine on the most delicate cycle you have. It cuts down on the agitation and really makes a difference on the fraying.

I wash every piece of fabric I get because of allergies. It makes a huge difference for me when piecing and quilting.

What I've found is that the raveling on the ends from washing isn't a big deal. I have to get the edges straight, as neither end is ever cut straight in the quilt shop. So most of the raveling is cut off when I square up the fabric.

My washer has a hand wash cycle that gently swishes, no agitation. No raveling of the fabric at all, even the fabric I tear.

I also don't prewash because it softens up the material so much I have to then starch the heck out of it to make it easy to work with. I've never understood the prewashing unless the fabric is coming from a questionable source, like Good Will or a thrift shop. On those occasions I've used a mesh bag which seemed to help some.

Wash on gentle cycle and then snip off any LONG threads before putting in the dryer. Most fraying happens in the washer, not the dryer, and gentle cycle is all it really needs.

This is what I use to do. I don't prewash anymore since I live now in an apt where we have to use the laundry facilities that cost 9 quarters for a wash and dry.

I've found that using a gentler spin cycle helps a lot. You could also cut along the edges with pinking shears to help prevent raveling.

If you don't have a serger just stitch a zig zag stitch on the edge before tossing in the washer. I use my old thread and odds and ends bobbins when I do this.

I prewashed a TON of fabric one year. My strategy was I didn't worry about it, because it's going to happen at times no matter what you do. And the piece that ravels will tangle, requiring that you untangle all the fabric from it. It was quicker for me to just solve all tangles as they came rather than attempting to prevent them

What I did do, however, was before throwing in the dryer, I detangled all snarls and I trimmed the major threads off (not everything, just the bad guys. And I saved them all! so now I have a huge ziploc bag full of lovely clumps of thread. Someday I'll lay them all between twin pieces of soluble interfacing and will sew a network of thread over them to hopefully create a new piece of "fabric".