Shooting smoke is fairly simple, the most important factor being light (it always is in photography). Instead of having a fast shutter speed, you will need a flash unit to freeze the smoke.
Depending on what kind of picture you want, and the ‘depth’ of the smoke, you will want to set an aperture between 4 and 8. Also, you want to get the sharpest possible picture, so use ISO 100 or 200. This leaves shutter speed. Similar to when shooting water-drops, the shutter speed isn’t going to matter all that much as the flash will do the job of freezing the photo. What you will need to do with this method, is make sure there is no other source of light, otherwise it will show (because you are using a slower shutter speed) Here are the settings I used when shooting:
Exposure: 1/180 sec
Focal Length: 21.3mm
Pentax AF540FGZ Flash
Remote controlled Shutter
Next you will need to set up your smoke source. You will need to be in a room where there is no draft. Incense sticks are relatively easy to use. I tried with a cigar, but found the smoke dissipated fairly quickly. Make sure you have some newspaper down to catch the falling ashes. Also, you may want to use a black sheet as a backdrop.
To get swirls and such in your photos, just swipe a thin stick across the smoke trails. Be creative, you can mould the smoke to any shape given enough time.
Here are some shots I took a while back:
Inverting the photos makes for an interesting change. Add some colour with Photoshop and you have some interesting smoke photos. As simple as that! Keep in mind that you may be taking many, many photos to get one or two good ones. Also, don’t feel that you have to use the recommended settings, this is just one of many ways to take photos of smoke.