When I made mine, I used John Flynn’s templates which, I think, are similar. It was pretty easy doing the curves. Personally I don’t like the look of the interfacing along the edges. I made a pumpkin-seed type shape using lightweight interfacing, right sides together with the fabric, sewing along the edges, and turning right sides out. When I went to do the stitching along the edges, it wasn’t as clean and crisp like I wanted. But that’s just my opinion.