I machine stitch my 2.25" binding to the front of the quilt lining up the edge of the binding with the edge of the quilt. I use a .25 seam allowance. After the binding has been attached, I use my long ruler and measure .5" from the seam where I've sewn the binding down. This leaves an extra .25 inch of top/batting/backing to fill the binding when I hand stitch to the back of the quilt.