It is fair to say that at some point most photographers be it pros or hobbyist's, will at some point try to photograph smoke!
This is where i found myself this morning before work.
I set up two light stands, one either side of my kitchen table. I took my roll of black paper and put a expandable handle through the roll and secured it to the light stands using clamps.
I then pulled the paper down and made a seamless background and used masking tape to secure paper to the table.
I then set up my speedlite 580 ex ii to camera left and at 90 degrees to where the joss stick will burn. I put a flag on both sides of the speedlite to stop light spilling onto my background and to stop the flash hitting my lens causing flare. This creates a corridor of light where, hopefully your smoke will be dancing!
The speedlite was set to manual and had power output set to 1/16th and 1/3rd
The camera was my 7D in manual at 1/250th sec F/8.0 Iso 800 and i used manual focus
The flash was fired with the 7Ds built in wireless transmitter
I used a ISO of 800 because this allowed me to have the flash set to a low output meaning my recycle times were fast so i could just keep shooting.
I also found i got better results using a longer focal length selecting just a section of the rising smoke, this one was taken with the Canon 70 - 200mm F/4.0 L USM at the 200mm end.
After the shoot i import the images into Lightroom, i look at all the images and reject any non starters as i go using the x key. After looking at all i delete the rejected images using shortcut key CTRL Backspace.
I then make my image choice to work on and take it into the Develop module.
I then increase the exposure very slightly to boost the white smoke, increase the contrast boost the blacks to give a solid black background and then use the white slider to regain some of the smoke detail.
I like to increase the clarity slightly and the vibrance and saturation. That's about all i do in lightroom, i have got a preset metadata set up which applies during import and just includes my copyright info title and my contact details etc.
From here i then right click image and select edit in CS 6.
From here i select the crop tool and make my crop as desired.If you want the rainbow effect you need to create a new layer. By default this new layer will appear above the smoke layer in the layer menu on the right hand side of screen, you need to drag this layer so it is below the smoke layer.
You then turn off the smoke layer by pressing the eye to the left of the smoke layer you should now see a blank layer. Make sure you select the blank layer in the layer menu and then choose the gradient tool from the left hand menu. This is hidden below the paint pot icon, just select and hold paint pot icon to reveal the sub menu.
Along the top above the ruler you should see a menu where you can choose the type of gradient you want
The one i used was the transparent rainbow.Then you apply the gradient by clicking and dragging over the layer either from top to bottom,left to right or diagonal as i did.
You should now have a rainbow covered layer.Go back to the layer menu and re enable the smoke layer which will now show and you loose the rainbow, all you have to do know is to change the blend mode of the layer to Multiply, this can be found above the layer menu to the left of the opacity it says normal by default , this is a drop down menu just choose multiply and see the effect appear in your smoke!!
You can try some of the other blend modes for different effects. I hope this has explained it well enough and gives you some tips on how i created it. There may well be other ways to achieve this as ever with Photoshop there is always more than one route.
Hope you found this helpful and gives you the inspiration to give it a go yourself, its a lot of fun!