One of the things that fascinated me about Karate in those days was how experts were able to chop, punch or kick through wood or concrete with their bare hands or feet. The trick, I was told, was to focus the strike to a point beyond the thing you were trying to break and to carry the strike through.
A crucial aspect to achieving high performance through communications in projects is this: we must break out of the silo that we describe as the life cycle. As the karate black belt aims for a point beyond the block of concrete, we must communicate beyond delivery. That is to say, talk about life beyond the project. Our clients are often not the least bit interested in what we deliver. Rather they are more concerned about how they will use the stuff we give them, how it will change their working patterns, how it might make their lives better or worse.
Even during our life cycle, we will gain much more engagement with our clients if we discuss what we do in terms of how it will effect them beyond the end of the project.
So communicate with punch, aiming for a point beyond the end of the project. (But try not to yell when you do it ... I've found the analogy with karate breaks down there...)