I too used Bonnie's method but did sew toward the first seam with the second wing. When sewing the two halves together, I squared up the corner and held it in place with a clover clip. I matched the pieced block up to the triangle and eased if necessary to keep the pieced triangle matching the solid triangle. I haven't lost a point and only needed to trim those "ears". It takes me a little time but I really like the results especially when assembly starts.