Last is the smoke example. It's very similar to the waterfall, except there's a lot less particles, the spin is much slower, and the particles are moving more slowly (since smoke tends to rise more gradually). You could also try playing with more wind modifiers to create some rather interesting swirling smoke effects. As far as the material goes, the noise size is slightly smaller, The colors of the opacity map are much softer so the smoke is more transparent, and I also tinted the color slightly blue to add some variety.