I often relax my body through closing my eyes and like most release the tension in my sowly.There are many different facets to this. However, I find i cannot relax the mind/brain in this way - it seems to tense a little.
This may be of help to others i dont know:
What I do is to visualize any scene in my head in slow motion. In fact slower than slow motion - a frame or two at a time yet fluid. It could be making a cup of tea, walking out the gate or opening a letter......
Doing this seems to relax the brain a great deal
Hope this helps somebody