First off, regarding nature vs. nurture: Achievement and intelligence are not the same thing; someone who is trained into a high degree of skill in an intellectual area has some distinct differences from someone who fits there by nature. Creative problem solving, multi-discipline knowledge base, wide vision, etc. are some characteristics that are going to be prevalent amongst the "natural" crowd.
My recipe is:
#1 Open and honest communication with my kid
#2 Support his expressed needs
#3 Encourage and feed his curiousity (heaping and feeding are not the same thing)
#4 Anticipate some caveats I know of from my childhood and encourage him away from those paths or eliminate the barriers that lead there (e.g. unstimulating work in school)
I figure if I get #1 right, everything else is a lot easier.
