As someone who has made several hundred quilts, I agree with all the suggestions above and have several other things to add:
1) If you are pinning but still get bad results, the pins are too thick. I use the flower head pins, long and thin. My seams match exactly 99 percent of the time.
2) When piecing, I often use a quarter inch foot. If you don't have one, use a blind hem foot and set the wheel to a scant quarter inch, and tape the wheel down.
3) If I have any doubts about accuracy, I use a METAL measuring devise often found in fabric stores. I looked for a picture for you and didn't find it. However, it is a more or less square shaped irregular piece of metal about an inch or two square and has measurements for 1/4 inch, 3/8 inch, 5/8 inch, and more. This is a must-have notion for me.
3) I use leaders and enders to stabilize the pieces I want to be accurate (all of them)
4) I use a trolley needle, worn on my finger, as a stiletto. You could use a seam ripper to guide that last part of the fabric through.
Last edited by cricket_iscute; 02-21-2013 at 11:49 AM.