It has been interesting to read this discussion. I have never, ever, thought to unclip both feet. What would be the point? It seems dangerous to me. If I am riding my road bike in traffic (which happens sometimes when I ride through my town center), I unclip my left foot and rest it lightly on my pedal (Speedplays). This works for short jaunts. I have campus pedals on my errand bike, so it's not an issue at all. I just rest my foot on the flat side.
You just have to keep practicing until it becomes natural.