Over on terrainwench.blogspot.com from a couple years back, she took us through how she made her "Lizardmen Temple & Spawning Pool" here.
Also, on michaels.com, you can score a couple of nifty time saving pattern makers that, while made for adding textures to cake frosting, look like they might be worth trying out with other terrain making materials. Look them over here.
Finally, on the Grimoire of Miniatures YouTube channel, he has four videos of a remarkable terrain build starting with the video titled "Gloomholde Section 1 - Custom Made Miniature Wargaming Terrain." Sadly, the videos get progressively dark in regard to the lighting but they can still be enjoyed.