Thanks Chad, I can't really help with the settings as I will often take more than one shot of the same scene with slightly different angles and settings and once they are uploaded to flickr I choose my favourites.
The use of smoke is mainly a combination of Exposure, contrast and brightness, but you can also adjust the zoom and position of the camera to move in and out of the smoke to create very different levels of the settings I mentioned.
You can then use the aperture setting to smooth over rough or unwanted areas of the shot, which can also give you some unique effects.
Sorry I can't be more helpful, im not great with explanations, but other forum members are, and have written some in-depth tutorials on how the settings work and the way they affect each other.
thanks again for the comments Chad.