For me it depends on the fabric. If I am using a large print that I don't want to have to match, I will cut the borders lengthwise first, then cut the remaining pieces out of what's left. I always work it out on paper first so that I know what cuts I am making. I usually buy extra fabric, so I don't often have a problem with running out. Once when I did run short, what I did was to put a coordinating square in the corners of the quilt. It looked planned, so no one knew I screwed up but me!