How Do You Use a Neck Nest?

The way that somebody uses a neck nest at the beginning is not the same as you use it moving forward. You take it and then you tuck it in, and you let the oxiport on the back of te head hang over the pillow a little bit more. But i notice that as the night progresses, a movement or something that just doesn't wind up there, and i have to readjust it when i wake up.