Kat, letting him know that you like what he does is the very best form of nurturing abilities.

My experience (and study) regarding children and art, music, stories - anything requiring imagination and creative effort tells me that almost any child can be encouraged to excel as long as the environment is nurturing of that effort. Children are always hungry for approval, and their innate abilities are easily drawn out and just as easily suppressed. I've seen kids who were very promising in one area (say, music or drawing) completely abandon efforts in that direction just because something put them off it, often just a parent's lack of enthusiasm, or an older child telling them what they 'did wrong'. The upside is that they usually find some other area (I can't draw like my scornful big sis? Fine, I just discovered I like making stories!) towards which to direct their efforts.