I'm not a fan of long loops of yarn on the back sides of my shawls. If I have to carry up yarn, I prefer to trap the inactive yarn. The method I prefer traps the yarn during the return pass.
How to do this:
1) Stop the return pass where the yarn is being carried up. In the video, this is at the beginning of the row so I stop before the last yarn over of the return pass.
2) Bring inactive yarn to the front of the fabric.
3) Do the next return pass stitch. In the video, this is a yarn over and pull through 3 loops.
4) Move the inactive yarn back to behind the fabric.
The image below shows the back of the fabric where the inactive yarn is barely noticable.