I feel your pain. finally, I have figured out to keep the line on the ruler just a tad more...just a tad. Try it with scraps. Also, you can check your 1/4" by sewing on an index card. The lines are 1/4" apart. Good luck. I didn't read all the suggestions, but I know your pain.
Edited to add: use thin thread, too...it makes a difference.
Last edited by coopah; 11-12-2016 at 05:53 PM.