A - Go down through the fabric close to the previous row or area of stitching, about 1 down the row from where you will be coming up for the next stitch. The knot should be on the front of the fabric.
B - Turn the fabric over to the back. Change to a sharp needle and run the strand under several stitches until you are even with the place where you will begin stitching again.
C - Change back to a tapestry needle. Turn the fabric over to the front (the dotted line is the strand running behind the fabric), come up for the next stitch, and stitch as usual.

Ending a strand behind Nun's stitching uses two different techniques, depending on where the ending is in the row.

To end at the end of the row, run the strand back under the stitches. If you pull tightly, a sharp needle may be needed.

To end in the middle of a row, on the back carry the strand forward along the stitching path for 1 to 2 inches and enter the fabric. Leave the end of the strand lying on the front of the fabric.

Begin a strand as described in Diagram One. Continue to stitch. When you have stitched to where the old strand enters the fabric, cut it close to the fabric and continue stitching.

The corner

If you need to turn a corner, stop with a vertical stitch 2 threads from the next ditch. Complete the next set of horizontal stitches.

Complete all edges and corners this way.

When the edge is completed, cut in the ditch as close to the Nun's stitching as possible without cutting the perle cotton. If you want a fringe on the ends, instead of cutting close to the stitching remove threads horizontal to the ditch and outside of the stitching. Trim so they are even.