Hi,
I went to a crazy quilt show in Madison,WI last year and there were about 20 quilts. The blocks were all finished differently. There is no RIGHT way to make a crazy quilt. It is truly crazy! My best advice is to use a backing that helps stabilize the whole quilt. I made a crazy quilt for my daughter's wedding and it took me 5 years. It had 8" square blocks set 9 across and 12 down. No sashings and no borders. Unfortunately I used old clothing she found in resale shops and I pieced the backing with stretchable velvet. BIG mistake. She hung it on the wall and it wrinkles funny. I made it the size to fit her bed and since she requested dark reds and blacks silks and velvets thats what I used. Then she painted her bedroom brown. I was not happy, but she found a place to hang it and it is really a very lovely focal point for the room.