Marker training is the most effective training system I have seen in my 50+ years of training dogs. It's a black and white method of communication that is based on positive reinforcement.

Marker training provides the dog trainer (1) a motivational method of telling his dog "the instant" his dog does something you like, (2) a non-punishment method of telling a dog "the instant" the dog does something you don't like and (3) a motivational method of telling a dog that you like what he is currently doing and you want him to continue to do exactly what he is doing at this moment in time.