Start by cutting your surplus design fabric into bias strips approximately 4 inches wide. Sew these together into one continuous strip long enough to go all the way around your quilt. Then fold in half and press, wrong sides together, being careful not to stretch fabric. On your quilt you will want to round off the corners somewhat to make application of the binding go more smoothly. Now, with the folded edge toward the center of the quilt, baste the raw edges of your binding along the line you have marked entirely around the quilt.
Overlap ends and cut off surplus binding.
Stitch carefully along the basted line on your sewing machine. Remove bastings after stitching. With sharp scissors, very carefully trim entire edge of quilt to within about 1 inch of your stitching line. Turn binding to back of quilt and baste folded edge over the machine stitching. Sew into place by hand using a small overcast stitch like that which you used for your applique.