Consider "birthing" your quilt, and then stabilize it with pins (keep them going up and down, not across) or clips or glue dots which you iron into place, and then use a simple pattern; I love symetric waves about 4 inches long (and from far point to far point about the same). You need to mark the curves with chalk or..... Start at the top of the middle (roll the right side tightly for it will be in your machine's throat) and follow your line from top to bottom. I've used this simple pattern a lot, and, amazingly gotten a lot of compliments on those lines. It's not fancy, but I, personally, like my fabric design to show and the quilting to be very secondary. I got some almost clear material that you can get at craft stores and cut it into 5" strips (any size you want), made my curves by first putting a straight line down the middle of each strip, used a compass on top of the line to go from point a to point b, put the compass below the line and repeated, put it above....... When done I taped by strips together end to end. Actually I only made two strips because you can simply place the template back a couple of curves that you've already done and continue onward.
I'm not very worried about going off the chalked line a pinch... when the quilt is done it doesn't show unless you make a sharp correction jerk. Like any other quilting method you have to stabilize your sandwich before you quilt and I am finding myself happiest with Elmer's School Glue. Depending on you fabric you might want to do some glue dots from both front and back, just be be sure it is stabilized well. The best point is that it's simple!