No one ever mentions the method I used for quilting my large quilt with my DSM.
So here it is:
1. lay out your quilt-top, then batting. Making sure your batting is large enough find a nice way to divide in thirds. Each quilt is different so you need to look at yours and see what can be quilted nicely in the first go over.
2. mark two lines, with quilt markers, dividing the batting into manageable thirds. These lines can be gently waving and your markers should be on both sides of the line for matching later (registration lines)
3. cut and remove the two side pieces marking somehow "right" and "left"
4. Lay out the backing, spray the middle, lay down the middle section of the batting, spray and lay down the top
5. Now you are ready to quilt the middle section without all the bulk.
6. When this quilting is finished, fold back the top and the backing and with a wide zigzag stitch stitch the left side batting back in place (use the walking foot) spray this part and continue quilting, repeat with the other.
7. This method really works and it is easy to get that batting sewn together. It will hold with all the quilting you are going to do on it and the wavy line helps to disguise the joining.
Try this method on a table runner or small quilt and see if you understand the cutting, spraying, quilting, joining, spraying, quilting and repeating for you. That's what I did and found my next large quilt was not a struggle for me or my walking foot.
By the way, I think stitching in the ditch is the hardest kind of stitching you can do. It never goes as straight as one would like. Look closely at the picture of the hand quilted one on this thread and that stitching to the side looks great and is much easier even by machine IMHO. Also plan on leaving lots of ends (result of lots of starts and stops) and using an easy threading needle (spiral) to get them tucked in. I personally avoid pinning-they are always in the way.
Quilting a large quilt gives you quite a feeling of accomplishment-it just doesn't all have to be done at once-keep at it.