I find the easiest thing to do is to ALWAYS unclip left when approaching a possible stop. This is a priority over downshifting to start again. I like to kick off with my right foot when I start and maybe not even clip again until I'm past the intersection. I use SPD's. They have a set of platforms for one side but I usually leave them off. Am 53, been riding clipless for about two years, and have only fallen twice.
Both falls were within a week (some months back). I was climbing some of the really big hills around here and had just put a new 14-34T rear cog on my touring bike. On both occastions when I shifted up to the last gear the chain went past the gear and dropped between the cogs and the spokes an at the low speed and coasting uphill I came to a stop rather quickly.
As to breaking your fall with your shoulder, I think that is poor advise. It is a rather good way to tear a rotator cuff. Two rounds of cortisone shots and awaiting an MRI tells me I think I'd rather break a wrist. Rather, like a parachute landing, try to land on the soft body parts and roll.