You can make rounded corners (use a plate to get the curve); add a flange, piping, or cording between the binding and the border; use cording instead of binding (cover cable cord with bias binding); cut out the corners as for a quilt made for a four poster; make the edges hexagons or diamonds or any other shape (actually half hexagons, half diamonds, etc); overlap any edge shapes more than usual; and so on. If you go the wall quilt route, the possible edges are almost limitless.