Hi,
The only machine quilting I do is a stitch in the ditch with a decorative or at least zig zag stitch. I figure it strengthens the piecing. I like to use varigated thread in both the top and bottom. Some times I just machine tie the quilt by setting my automatic button hole to the smallest size, making a very small button hole without a hole and then lifting the presser foot and moving to another spot. I have a lot of strings to cut afterward but the buttonhole is backstitched at both the beginning and the end. Either method works well for Linus or other chairty quilts as they will be washed a lot more than those of us who quilt would.