Don't over-think it. I think just repeating "Unclip! Unclip!...." to one's self in the beginning as they're first starting with clipless, is 98% of it.It's just a matter of remembering to unclip just before/as you're stopping. Always be prepared; anticipate stops and prepare to unclip.

I'm new to clipless myself. Did my first two 34-mile rides without a problem. Then, preparing to leave on my 3rd ride, I stopped at my mother's on the way out (she lives on my property) to drop something off. I unclipped my left foot [Is that my "chocolate" foot? LOL] and just then, a gust of wind took the item I was carrying out of my hand, off to the right. I instinctively lunged to the right to try and grab it- but my vanilla foot [right foot, LOL] wasn't unclipped, and over i went! It was nice being on grass. Maybe I'll be lucky, and that'll be the first and only fall, and it's "out of the way" now?