A time saving and better sewing border tip I learned from a quilting perfectionist was if there was more than one border sew all the borders together first then you only have one border to add to the quilt. And to tiny zig zag around the quilt top before measuring.
Anyone remember a quilt show or video that showed how to guarantee no wavy borders by just sewing them on without measuring? I wish I could remember who that was. I wasn't into quilting that much then and didn't really pay attention.