Try one of these after you get comfy...

 

One way is verbal: Find a word like "empty" or "nothing" and whisper it back to yourself over and over again for several minutes until your head feels clear and you feel you are getting into a zone, which is when you notice your breathing becomes more automatic.

 

Another way is visualization: Picture yourself at a crowded parade with lots of people, marching bands, etc. going down your favorite street (childhood home, etc.). The key here is to let the parade pass by and let the people clear out until there is nothing but an empty, peaceful street. Keep the vision of the empty street in your head until your head feels clear and you feel you are getting into a zone, which is when you notice your breathing becomes more automatic.