I machine sew the binding and never use any clips or glue. Just cut your quilt sandwiches' edges nice and straight when squaring up, and then lay the binding in line with the edge. Keep a little bit of tension on it when sewing it and follow some stitch guide: the edge of the machine foot, usually. It can't be anything but straight if you do that.
One little cheater trick: You can correct some imperfections with your iron. When you take the binding around to the back, no harm done if you straighten up any curves by pressing the binding forward a tad, over them. This is only for shortages in the seam allowances, not places where you took too much seam. Those will have to be picked out and re-sewn. If you follow your seam guide (foot) you will have very little of this, ever.