I have found a really easy way to create realistic smoke in a picture. Since it's already posted on another web site, and since it uses the same basic principles that I use, I figured that this would be easier than posting the instructions and screen shots myself. You can view the instructions on how to make realistic looking smoke in a picture here.

Joseph,
I  wouldn't necessarily call them Photoshop "Tricks" but I did get a whole bunch of Photoshop Actions that I can burn to a DVD for you.

It's some pretty cool stuff, that is really customizeable. I'll bring a DVD to the next meeting. (it includes two different actions to make smoke)