IMHO you're doing a whole lot right! When I said I admired the stonework, I really mean it, carving that thing out of foam core is a real feat! The heavy stones along the corners look perfect! So while I will watch the video with interest, what really interests me is the foam core carving part. I guess the best way is just to jump right into it.
FWIW, my house in central France has similar styled corner stones, though the rest is brick. I'm told it's from the time of Napoleon 3, but the basic architectural principle is the same.