Been quilting long enough to know how....but don't.
Ok..true confessions time. I have tried over and over when sewing blocks together, to have the back seams lay properly. I have ironed, I have used pins, I have held my finger over the seam until I was almost one with the machine and STILL, I'll have a seam that gets twisted in the sewing, so that when you turn it over, the first part of the seam allowance will point left and the end of the seam allowance will point right. It really bothers me, but not enough to rip every bloody block out and redo it.
What's the secret? Or, is it really that most quilters have this problem?