I do a lot of quilting with my walking foot and have found that my needle jumps a stitch or two whenever I stop. So I try to stop at a seam. That seems to work for me. Don't forget that when it's all quilted and, perhaps, washed, your quilt will crinkle up a bit and hide those jigs and jogs. I mark with green Frog tape and also blue wash out pen most of the time. If the background is dark, I use a gray chalk pencil that rubs off. Enjoy!