When I first started practicing yoga, savasana was so challenging for me. How can I just lay here, and for how many minutes? My mind would immediately start making lists of all the things I had to do and what I was going to make for dinner (and it still does this, although to a lesser extent).
This article really sums up the things you can do to allow your mind and body to surrender in savasana. It is SO important to rest! We all know that, but many of us have a hard time doing it.