Another trick is it pinch your nose and try to breath through it. As you aren't really pinching your nose, your breathing is unobstructed. I got in a habit of c

Another trick is it pinch your nose and try to breath through it. As you aren't really pinching your nose, your breathing is unobstructed. I got in a habit of checking when I would see certain signifiers (like machines behaving in surprising ways) and maybe 1/3 of the time, I would find I'm dreaming.