First, I'd recommend trying rest, by which I mean lying down with your eyes closed. Beyond that, I would suggest trying various approaches and techniques to find one that works for you. For some, tapes are useful. Some people pray or meditate. I think the idea is to experiment and to have some patience with ourselves.
Relaxation is a skill and it takes some time to develop.
Deep breathing was very helpful for me. Lisa is a graduate of the course. We suggest people consider three different approaches, either alone or in combination. For some, experimentation with sleep medications is helpful. These are standard practices often recommended by people with sleep problems.