I always make king size quilts for my queen sized bed. Queens just don't quite cover to the dust ruffle. and, there is no worry about blanket hogs. They seem to come out nearly square too... somewhere around 100"ish square.
I have started using wide muslins for bed quilt backings. If it's on the bed no one sees it anyway - and it's not likely to get grungy like a throw quilt would - and no piecing backings
