• Set machine to a small stitch length (1.6 or 18 SPI).
• Sew SLOWLY. Set machine on SLOW speed if possible.
• Always start sewing on a piece of scrap fabric, leaving it attached to hold the threads.
• Sew units right-sides-together, with concave unit on top (Background Fabric).
• Line up the curved edges of the two units at starting end, leaving a small "dog ear" of the top piece hanging over.

And many more suggestions and tips are included with the ruler.