I cut bindings selvedge to selvedge to get a bit of stretch without resorting to bias bindings. I'm not too hung up on the weave direction when I cut my sashings. I always use cornerstones, I get much better matching when I do. With the cornerstones, the sashing pieces are going to only be the length of a block. What I do look at is the pattern of the sashing fabric, and decide which way would look best. If it's an obvious directional, I have been known to cut the sashing both WOF and LOF so that the pattern stays consistent.