I did mine a little different than the tutorial said to do it. I sewed my fabric wrong sides together and then sewed the edge down with a zigzag stitch. I thought that gave a nicer seam on the inside and outside of the scarf. Google taught me that this type of seam is called a False Flat-Felled Seam.
Depending on the fabric you may need to adjust either the length or width of your fabric to get a good thickness for around your neck.