I make maps for a living, not the ones that most people are used to, but maps none the less. The brief amount of time that I have spent tooling around with the terrain editor had brought me to the conclusion that it is "clunky". Now, I like what I do for a living, but I do not necessarily want to eat away at my free attempting to create a terrain.
There are tools in the AH3 terrain editor to create automated elevation features in a single button press. I suppose I should learn them but, I had too much fun making the land ala "mud pie, la sand castle fresco". The biggest thing is the repetition and time involved. After all the time I spent carving water cut geo features, it's now pretty second nature how land and it's features should flow.
You can see it in any landscape photo on the internet so no one has to reinvent the wheel. And the elevation tool works better for me if I just chunk down single elevation blocks of land and rapidly remove everything that shouldn't be there. Like stacking blocks of ice on each other and carving Mt. Reiner out of it with a chainsaw. It's really the picayune of field placement and creating the resupply system that consumes time because you have to visit every field you place on the map to make sure all the spawns and towns work. And a check list of conditions to meet acceptance to the MA from Skuzzy.
There is a tool that will automate the terrain tile painting based on elevation. Personally I found tile painting to be like using the elevation tool in the ability to paint trees, clutter and rock if you get a handle on how trees, clutter and rock with show up from landscape photos. I am told you can import properly formatted geo maps to auto create real world locations. I'll leave that to the AvA and SEA guys who are really fantastic at creating terrains. I think Easycor could quickly bring you up to speed on it. And Artik has created a program to help accomplish it.
Fugitive:
I have a gunnery training terrain for offline I will release to newbies when AH3 goes live. I use it for offline bug testing in the beta. You can create AH3 terrains now and simply run a build against them with every beta patch Hitech releases. Then test that for any bugs like I have done since I created it back at alpha 87, and then run it when the AH3 download is forced on all of us. It's not very complicated......and Easycor and Greebo have written a great how to manual.
Just don't be a south bound rodent's hole like me and I'm sure they will help you get your creation into the game. Both are very good at creating terrains.