If you have the option of doing a decorative stitch that swings back and forth over the line, it covers a lot of the crookedness that shows up in SID when you can stay in the ditch. Just an idea. I like the scallop design for this. I also use a zig-zag stitch as well as a "joining" stitch (#074 on my Elna and #18 on my Bernina Activia 135).