An alternative to SID - sew decorative stitches as the 'quilting'. Definitely need a walking foot so that the sandwich feeds evenly.
Like the little zig-zag Amma suggests, this is more forgiving that SID. I often ended up with the decorative stitching along the seamlines, or echoed. My machine only has a few stitches that I like for this, but that's enough to give some variety and interest to the quilting.