A walking foot works beautifully on stitch-in-the-ditch quilting or lattice quilting. Use an embroidery or as PaperPrincess suggested a hopping foot or darning foot to do free motion quilting - that is when you want to drop the feed dogs so you can move the quilt any way you want and not be fighting with the feed dogs that are pulling the quilt through in one direction. Practice first and enjoy the learning process.