Creating a Smoke effect in PS7?

[CDailey]

How do i create a smoke(squeeling the tires/white smoking) effect in PS7.

 

[KosmikFool]

I make my own layer thenI use the blurry paintbrush in a grey color at about size 15 over the spot where I want it, then I use the liquify filter and then the gaussian blur filter.

But thats just what I do.