Since at home is where the majority of the problems lie, then that is the best
place to start - where the dog can be the least distracted and most receptive
and you can learn how to make your problem solving pro-active instead of
re-active. Good manners begin at home.
Also, the home environment can be a major contributing factor to the behavior
of the dog and you, the owner, are included in that home environment. Making
you and your home the most comfortable environment for your dog to learn, and
easiest for you.