Margo has a great tutorial to help you get your 1/4" seam just right. I found out the hard way that being out by even 1/16th of an inch on a long pieced border that you can fall short by as much as 3"! Here's the link.
[url]daily-blog/103-good-advice/14745-margos-test-for-14-seam-accuracy[/url]
If you go to the classroom Sue Garman has some useful tutorials on paper piecing and accuracy with measuring,cutting, sewing and pressing.