Measure and mark two same size fabric panels in a size equal to the desired size of your yard flag, plus 1 inch on all four sides. Add an additional 2 inches to the top of one of the fabric panels. The extra inches are for seam allowances and for the pocket hanger allowance.
Cut out the two fabric panels on the marked lines. Place the panels face to face and pin the two sides and the bottom of the flag, 1 inch from the edge. Leave the top edge open.
Stitch the three pinned seams together along the pinned lines. Remove the pins as you go. Leave the top open.
Iron the seams open around the perimeter of the fabric panels. Reverse the fabric panels through the top opening.
Fold and pin the edge of the longest flag panel ½ inch. Iron the fold flat and remove the pins.
Cut a piece of fusible tape equal to the width of the top of the yard flag. Attach the rough side of the fusible tape along the 1/2-inch ironed seam of the longest panel. Remove the paper backing and fold the long flap over onto the front of the shortest fabric panel. The fold should create a pocket along the top edge. Iron the seam along the fusible tape, pressing each section for 10 to 15 seconds.
Slide the top pocket over your yard flag hanger.