I pin and pre-sew across the intersections (about two inches) with a 4.0mm stitch length. I then check the front side to see whether the points are matched and sharp. If all the points match, I sew my regular seam allowance and stitch length, simply sewing over the pre-stitched areas which now serve as guides.

Hi Stella, I just did a quick search for this problem. Perhaps this resource will help?: http://quilting.about.com/od/quiltsettings/a/settingtriangls.htm