So one of my friends went to a Ricky Tims workshop and he said he grabs each piece of fabric and pulls hard! This doesn't work if you are ripping something with pieced blocks. Just yardage. You have to be committed and yank hard. At our quilting group when she told us this we were all shaking our heads saying, no no, can't do that. And she took what she was working on, stood up, and yanked hard and wow, it all came out and nothing was stretched. I'm sure this doesn't work on bias, but on straight seams. We all gave it a try and now we are convinced. It was a hard lesson but very easy.