I unclip both, but it's physically impossible for me to sit on the saddle and "plant both feet on pavement" - I'd be on my tippy-toes if I could reach with both feet, and the road is generally sloped away on the right side. Which, naturally, is the side I always fall towards.

(not to mention that every time I lose a screw and can't unclip, it's always the left foot that gets stuck to the pedal)