It was particularly helpful for me to be able to see David’s entire face by looking over the top of his head into the mirror he held in his hand. I quickly got used to “seeing” in the non-reversed mirror and so could avoid touching the left side of his face, poking him in the eye, or holding my hand in front of him so that he could not see himself in the mirror.
It was also helpful because it was very hard for David to pay attention to the mirror for extended periods of time. After a while, watching someone touch your face is just not all that interesting and so is hard to do for very long, similar to meditation. So part of my job was to watch where David was looking in the mirror and to stop whatever I was doing when his eyes strayed elsewhere. This would always get his attention and he would come back to focus, at which time I would continue the massage.
When we were traveling, our mirror was too small for me to be able to see much of him in it. By that time I had practically memorized his face, so the technique wasn’t hard, though I do wonder how much he let his mind wander. Still, who’s complaining—it worked!