Now comes hardcore part. Create one 3d fluid container. I don’t want to explain fluids now, or else this tutorial will be very long. Just hold presets button in attribute editor while fluid is selected and find Clouds or something like this.

Also you can change falloff method to something like sphere (it’s in shading tab).

Create another fluid container and set preset to skyFog or something like this.

In incandescence tab change ramp colors to get the mood you are seeking for.

So rendered, it’s starting to take shape.

From this point I used Mental Ray for rendering, since it renders fluids very fast.

Change shadow type on light to raytraced.

Now, trees. Open Visor, scroll down to trees mesh, and select the type of tree you want to use.

In paint effects tool settings (the icon shall pop up in toolbox. Just double click to get options), change display quality to something like 20 or so. Also you can turn off draw as mesh to get more speed.

In template brush settings (In paint effects menu), change scale to mach the scale of your scene.

Here I used OakForest brush to get distant trees.

Then go to modify/convert to polygons and set the numbers really high.

Now speed in viewport will drop. Assign trees to layers, so you can hide it.

Then change tree type in visor. These trees will be real 3d, so prepare…

Select ground, and make it paintable (in paint effects menu, make paintable), draw few trees onto mesh.

Convert them to polygons.

Then don’t draw the new ones. Just duplicate existing trees as instances. This will save render time a lot.