Smoke Effect in 5 Steps

[Xcellent]

here is another smoke brush..

EDIT: I should mention the brush only works on dark backgrounds since it's lightening up dark areas only. It doesn't work on a white background.

Ungroup all elements, then select a stroke, open up the brush settings and see the parameters. Each stroke has different brush settings (except the word 'smoke' uses the same setting for each stroke). I used different sizes of the same brush-shape but with different settings for each stroke.

The brush-shape itself is a simple rectangle with a transparent stage fill.