A slip stitch is used to make an invisible seam between two edges. A slip stitch can be used on quilt bindings, to close a lining, or to apply an applique. One way of sewing a slip stitch is to fold down both edges. Run your needle through the fabric on one side of the seam and then through the fabric on the other side of the seam, running parallel. When you pull tight, the seam will close, with the folded edges coming together in a sort of kiss.