Some patterns are cut at 1/8" increments to avoid the use of templates. When I had numerous HST and QST's with odd measurements, (like McCalls USA quilt in my posted thread) I invested in the Triangulations CD. It was a life saver. I could make a whole computer sheet of triangles in the correct size without lifting my needle, using the continuous line method. If you cut your own slightly bigger as suggested above, just make sure you square up each unit, whether it is triangles, nine patch, rectangular sections etc. BEFORE you sew the units together.