When I first started my clipless about a month ago, I always remembered to prepare to unclip like 100 yds away from a potential stop (stop signs, traffic lights, etc.) so I can assure myself I won't fall over and make a fool of myself After a couple of weeks, it became second nature (like some have said) to me and I can unclip even in sudden stops. One thing to remember is to loosen the tension in your pedals so it would be easier to unclip.