I'm one of those hobbyists with ambitions greater than my time and energy, so I never finish the terrain projects I start.
I've been pondering the wisdom of a fellow hobbyist on our blog, the Corvus Cluster, who is focusing on small, easy-to-finish terrain pieces. And he's gotten a lot more projects completed than I have (by a 20-to-1 ratio).
So, is thinking small thinking smart? Take a look.