I think the 2 most important things when piecing, is the cutting and the 1/4 in. seam. Even a 1/8 in. goof, can be a big mistake at the end of a row. I am not the quilt police, but until we can get that right, we are going to have problems getting things to fit. Which I have to say, I sometimes do. But everytime this happens I hear my Dear Mother say " If it's worth doing, it's worth doing right!"