i fully agree - thats exactly how i work, just see the basic shape, a rectangle, a circle, and start whittling away. - but most of all, have fun. - once you read the basic tutorials on the terrain editor then you'll discover even more possibilities.
and there is so much satisfaction in creating your own models etc, than  just importing something pre-made.

Experience is no substitute for blind faith.

http://avalon2000.livejournal.com/ - My Art Blog

http://jeferies.jalbum.net/Richard%20Jeferies%20Future%20Perfect/