This is my personal opinion only: When I did my CW quilt I used blocks from side to side, top to bottom with only 2" sashing in-between. Because I feel like if they had been fortunate enough to have a big piece of fabric they'd have made a shirt or a skirt with it. I wanted mine to look scrappy and with small pieces. It was a BOM so some of the blocks weren't what I would have picked. I used strips of the left over fabric, no set length, no set color combo, just a little of this and a little of that for the binding. It's not quilted yet.
http://www.quiltingboard.com/t-39959-1.htm
here's a picture of mine, you just have to turn your head sideways to see it. LOL