A while back I told you about some free smoke textures you could download and use in your Photoshop designs. But if those textures didn’t quite fit your needs, perhaps you would be better off creating your own texture backgrounds. QBrushes has an awesome set of 21 free smoke brushes for use in Photoshop. Using them on top of color backgrounds and messing with the layer settings can yield some pretty cool results!
really cool brush set
photoshop cs4 brushes