Place the strip for the binding wrong side up and fold the right hand end corner over at 45 degrees and press. Figure 1. Fold the binding in half wrong sides together across the width making the strip 1¼ inches wide. The right hand end will now have the raw edge from the end folded inside which will act as a cover for the other raw end of the binding when the two ends meet on completion. Figure 2.
Place binding on the right side of the quilted square with the long tip of the folded binding about 1½ inches from the corner above it. Line up the raw edges with the raw edge of the quilted square and pop in a pin to hold in position. Start stitching about 4 inches from the tip of the long point which will be fairly close to the next corner to leave open the 'pocket' made by the folded binding to take the other end when joining. Stop stitching ¼ inch before the corner. Figure 3.
Carefully remove from machine. Turn to start down next edge and fold binding at 45 degrees back towards top edge. Figure 4.
Fold binding again forwards over the 45 degree tuck with the binding fold being level with the edge of the previous stitched side and the edges of the next length to stitch being level with the side you are about to sew. Put back in machine and stitch this side right from the top folded edge through all thicknesses along to the next corner. Figure 5.
Do the same process for turning this corner and for the remaining corners. As soon as you have stitched clear of the last corner, stop and remove from machine. Measure and cut the binding to have enough to tuck completely into the 'pocket' created at the start of the binding application. Figure 6.
Carefully tuck the end into the 'pocket' (edged in pink) and keeping it fairly taut stitch from where you stopped through to where your stitching started. Figure 7.
Now roll the binding over to the wrong side Figure 8 making sure the corners sit well.
Pin in position and then stitch binding by hand in place on the back. You also may need to neatly stitch the join to prevent any gaping where the 'pocket' covers the end of the binding.
Finished binding Figure 9.