I always pre-wash and I cut the corners. Works very well, even with the not so good quality fabrics.

I serge mine. It take a little time, but sure makes the fabric more manageable. You can use a zig zag on a regular sewing machine too.

Ditto - or use the serger around the edges on rolled hem.

Pinking shears are great, not washing is the best.

I usually wash so much fabric that the use of pinking shears would leave my hands a bloody, blistered mess. I think knots are just part of the process. Maybe save them to use in an art quilt? Toss them in the shrubs for the birds to nest with?

i do not usually prewash fabric, but if i have reds, or something that does need washing, i do it by hand, soaking, rinsing til it runs clear, then drying to a dampness, then ironing dry...no threads or knots...

I have a separate rotary cutter with a pinking blade. It helps.

Ditto...

When I do prewash which isn't often. I zig zag the ends together (not selvage but cut ends) and then after it is laundered I us my rotary cutter and ruller and slice that little bit off. Works well and minimal loss of fabric.

Yes this works, set up one rotary cutter with a pinking blade for just trimming cut edges of fabric. This does help and is far less time consuming than sewing, serging etc.