Matthew D. Innis has a really interesting discussion about the amount of work one puts into creating good images on his Underpaintings Blog.
It will resonate with anyone who has ever agonized over getting an image right and the days/weeks of struggling that can go into it.
It is easy to look at the finished piece and say "that looks easy to do" when it really, really, really is not at all.
(I suppose you could say that about a concert pianist or ballet dancer as well... It looks so effortless when thousands of hours have been put in to make it appear that way).