Hi, I look to my Thimbleberries book of quilts many times for ideas and tips and tricks. Their advise is to cut your square (that you will later halve into two triangles) 7/8" larger than the desired finished size of the triangle pieced square you want. For example: if you want a 2" finished square then you should cut each square 2 7/8". Then just pair the desired triangles from these larger squares together and sew the diagonal with a standard 1/4" seam. Hope this makes sense and happy stitching! :)