One thing that my wife and I have always been very careful to do is to separate the person from the job. What I mean by that is when one of my kids do something well, whether it is one of their assigned jobs or coloring a picture, we tell them "good job" instead of "good boy" or "good girl". This way, their worth is not tied to the job they do. Saying "good boy" may be fine when they do a good job, but what about the time where they do a bad job (and we all do that)? Does that mean they are a bad boy or bad girl? Not at all. I can always tell that they get this when they say "I did a good job, Daddy!" after doing something well, and I know they won't think they are a bad person if they don't do something well.