I've always loved the beautyful environments and landscapes of the Infinity Engine games, especially the outdoor areas of BG1 and IWD.
I also was disappointed that most of the mods only reused old areas or recombined at most.
So I started 6 week ago to find out how to create my own areas and with the right tools it is actually not that hard.
I looked into 3DS max, but was not happy with it. So I stumbled across Blender and gives you almost everything you need to create your own areas from scratch.
Here is what I've achieved so far.
Two month ago I had never dreamt of being an environment artist and I have done a pretty good job for the start, I guess.
The best thing about Blender is that ist is free and that you a lot of built-in plug-ins to shape the landscape you have ever dreamt of.
For creating the landscape itself you use the ANTLandscape plug-in.
For trees you use the Sapling Tree Generator.
For walls and castles there is a Masonry plug-in.
For placing all of the stones and plants you can use the built-in Particle System (also useful for creating animations, both character and spell)
For grass use the Hair Simulation.
To destroy, build or deform things use the Modifiers.
Assets like buildings, trees, plants, items can be found everywhere on the net for free (you can use .3ds, .obj), so you don't have to build it from scratch.
All of the shading is done by Blender itself. You only have to experiment with the properies of environment lighting, ambients,...
You can find thousands of free hi-res textures by using the Google image search.
How to start:
Download Blender and Gimp (for edit textures). Crazybump is also very useful the create normal , displacement and specular maps in 5 minutes.
Find some nice tutorials on Youtube. There are hundred of good ones for every aspect of the application. First focus on general usability and landscape creation / texturing.
Create your first landscape with the ANTLandscape plug-in.
Set your camera to isometric view (Orthographic camera 45° view). zoom that it fits your landscape.
Add some textures to it (grass, cliffs,...) For blending texures on you landscape use stenciling.
Create a normal map of your texture to get more 3d feeling.
Add some cloud textures to your landscape to create an irregular surface.
Add a sun (raytraced shadows). and Sky
Set the render properties (resolution 5120x3840, anti-alias)
Set the world properties (add some enviroment lightning, ambient occlusion)
Render you scene (Took me 10 hours to render the attached area, but you can switch off shadows, anti-alias, enviroment lightning, ambient occlusion to reduce the test renders to 5-10 min, also reduce resolution).
Add some water (make your material transparent, shiny and reflecting. add some fresnes effect)
Download some trees, plants, buildings items like barrels, carts,... and place it in your scene.
Try the modifiers to create and modify models (very useful is Mirror, Array, Build and Solidify modifier).
Use the particle system to randomly, yet controllable spread your plants and rocks over the surface.
Build your own models, rearrange others, texture them like you want them.
Use groups, layers to manage your scene.
What you can also do:
Create your own animations. Create or download a character. Animate it. (I haven't done this, it certainly is much more difficult)
Create particle effects like spell animations (should be easy with the particle system)
Be creative, use your imagination and have fun.
I can send you some blend files to show you which preferences I used.