Some beginner ramblings.... (its hot here in Canada)

[Oshyan]

Simple Shape Shaders are very helpful for explicit placement of features, displacement, etc. You can also warp their shapes to get more organic, natural-looking shapes to affect the terrain. Painted Shader is another good option for explicit adjustments.

We are working on some more project-based tutorials for future release.

- Oshyan

[WAS]

... Painted Shader is another good option for explicit adjustments.

Just be sure to let the 3D preview fully render (HD is best) and than pause it. Give one test brush stroke for TG to realize you're actually painting, and than go nuts. The paused preview will allow you to do multiple brush strokes as if in Photoshop or something without the preview re-rendering and making your precision go all over the place, or hitting the preview boundaries and accidently painting all the whole view-port through exploded polygons (seams from off-camera).

Hopefully one day we can use a rendered image to transpose to paint on for absolute explicit control of where strokes are applied seeing what the resulting image is.