You can achieve some pretty neat effects with the stock decals alone and a bit of tinkering with the particle settings. Something like this;
(It might look a bit weird, had to decrease the brightness a bit due to the super-heavy bloom.
Also the fire's a bit large in comparison to the smoke pillar, twas just a test though.)
This is just using a medium fire decal without particle settings, and the black smoke decal with particle settings. Unfortunately I don't have the settings saved anywhere, but it was pretty straightforward. High constant motion upwards, a bit of random motion along X and Z, and a low life increment so it animates slowly (10-20).
It'll be interesting to see what people can achieve with custom effects. I'm tempted to do some experimentation myself...
