I think you want to sew all three (backing, batting and front) together at the same time. You can make a different design in the borders...lines, Xs, just about anything. But it sounds like you are planning on sewing the batting and back together first and then sew the top on it. I may have read it wrong. But if that's what you are planning on doing, don't. You are making an extra step for yourself. I'm proud of you to make your first quilt and want to quilt it yourself!!! And on your own, you added borders. You are doing terrific for a beginner!!