I unclip my left foot (the one I plan to put down) as I approach a red light or stopped traffic. I may slow down to a crawl to keep my balance without actually stopping if I think it is about to turn green. When I do stop, I make a decisive turn of the handlebars to the right just before I stop moving and need to put down my foot. This ensures that I lean turned my unclipped left foot. Afters stopping I move my right foot to the forward/up position and leave that foot clipped in.

To restart I stand up on the right pedal and sit down as I start moving forward. I clip in the left foot when it feels right, sometimes on the first revolution, sometimes later after I have passed through the intersection. The SPD/platform pedals are more forgiving than single-sided pedals for stepping on the wrong side of the pedal when starting.