Save a strip of backing fabric to make it less visible. Cut it 4-5 inches wide and the same width as the quilt top edge. Press in half. Press 1/2" in on each edge.
Attach the sleeve to exposed raw edges AFTER the binding has been applied to the front edges of the quilt, but BEFORE the binding encloses the raw edges.
Sleeve is folded lengthwise, centered along the edge, raw edges pinned even with quilt layer raw edges.
Turn the layers over and RE-STITCH along the stitching line that attached the binding to the top edge. This picture shows single thickness binding. You can see the previous red binding stitching ahead of the presser foot.
Folded-over portion of quilt top edge shows sleeve end stitched in place (white thread). Lock stitches at ends of sleeve.
To finish sleeve application, HAND-BASTE along the fold edge (you can see needle stitching) but only through the backing and into the batting of the quilt, so it doesn't show to front side.
Also turn the binding to the back of quilt and finish as usual. Here it is pinned in place for a few inches.
Here is a closeup of the hand needle joining fold edge to backing.
In the image above, you can also see a wooden slat inserted to simulate how the sleeve will work. This setup is for "invisible" hanging. The slat protrudes one-half inch or so from each end of the sleeve, but when cut to proper length, will remain unseen behind the quilt. Small holes are drilled through the slat. Wire nails can then be used to attach slat (and quilt) to wall.
To avoid nail holes in a wall, many other styles of hanging systems are available. This sampler quilt is hung using the "Hang Ups" system of wood & thumb screw clamps. The slat in the quilt's sleeve fits between the front clamp and the back plate, then screw is tightened to hold it.
I have "permanently" attached the clamps to the wall, finding studs for secure attachment. This allows for switching out of seasonal quilts.
Sometimes a quilt that is already bound need preparing to hang on a wall. Follow a similar process, as was done for this bed quilt. Cut, press in half and press ends in as described previously. But then, re-fold face sides together, and seam the long edges. Turn right side out, fold end creases inward. Pin in place at quilt edge next to binding. Whip-stitch at lower edge of binding, securing stitches through many layers without showing through to front. Stitch lower fold in the same manner as described above.