See EarthMover´s tutorial here: http://forums.sketchucation.com/viewtopic.php?f=323&t=21379&hilit=plugin&start=30

Subdivide and smooth (now Artisan) http://forums.sketchucation.com/viewtopic.php?f=323&t=34868&hilit=plugin can also be used to achieve such results, but it will take some playing with to understand how to create proxy's.