I heard a phrase once that really, really made an impression on me - 'Perfectionism is the enemy of Creativity'. And, it truly is. I tell my students that they usually do not make mistakes, they add design elements! You are making the quilt, you get to add/delete things as you choose. Others will see what you make as a wonderful gift, a work of love and heart. We need to stop being so hard on ourselves and get back to the joy of creating the piece. We tend to drive ourselves crazy over the little things that no one will ever see or care about.