I have never been happy with the pillow case method of sandwiching. It always manages to shift. I have found the best method for me is to iron the sandwich and get it matching as close as possible. Then I pin it all over, start quilting from the middle out and leave about a 2 inch unquilted border all around the quilt. The unquilted border allows for any extra fabric to be less noticable because it puffs up a little. This would also work if your tieing it, just make sure to follow batting instructions for the space between ties.