Um... first I did like Amy said and perforated the lines. Then I laid A1 right side UP on top of the paper block. Then I took piece A2 and folded one edge toward the wrong side (where my seam would be) and set that on top of A1 where the line was... lining up my folded edge of fabric with the stitch line.then I just flipped A2 over so that it was RIGHT sides together with piece A1. I put a pin in the back and flipped it over so that I was stitching on the paper with fabric beneath. Stitching thru the back of the paper wasn't a problem because the paper was perforated so I knew right where my lines were. I hope I explained that in a way that is understandable. I just, I watched the video and it just seemed so complicated. But I did it my way and it went super quick. I did the same thing for the flying geese blocks too.