Nutrition has a lot to do with it. BUT - as far as grooming goes, I always add baby oil into my bucket of shampoo. Not only does it make the coat soft and shiny, the water will bead up a bit and roll right off of her if she's out in the rain. Other threads on this forum suggest vinigar in the water. I can't wait to try that! I bet it also keeps the flies away.
No hour of life is wasted that is spent in the saddle. ~Winston Churchill