Welcome from the Michigan Mitten. Your questions are often the questions we all have. I generally do either straight line stitching, up and down and across, or I do diagonal cross hatching. Both are easy can be either close together creating channeling or about 2 inches apart. Depending on the quilt, I also do wavy stitching. Mine are freehand. I don't use the expanded wave stitch on my machine, I prefer to to make my own waves and then I follow them at about 2 inches apart. I like the look of he freehand waves. In the end, it is what pleases you and is fitting for the quilt at hand.