Hi robin, many people tell new quilters to stitch in the ditch, however, unless you sew a very straight stitch, or your thread blends in REALLY well, I would avoid it. An easy method is to outliine quilt 1/4" away from your seams on either 1 or both sides. You will need to make sure you test your tension and thread on a sample because it will be very visible, but it is easier to follow in a straight line, and causes the seam to pucker, which looks beautiful on quilts. When you stitch in the ditch, there is very little leeway. If you veer off just a little, it stands out like a sore thumb.
I have found that on my walking foot, if I move my needle over to the right position, it is exactly 1/4 from the edge of the foot, so I can easily follow a seam.
I use this on my strip quilts, and on some applique, you can see it here:
https://www.etsy.com/listing/175953979/baby-quilt-woodland-animals-deer-and?let me know if you have any more questions. I'm glad to help!