I don't know about Wool, he's gonna be loads better at this stuff than I would be, but I just experiment. Tripod, small flashlight, shutter release, dark room and a subject. Set the ISO low, aperture to whatever you want to create the DOF, and a shutter speed for a few seconds. Turn off any lights making it black, or at least really dark, engage shutter and for about a second, lightly touch the subject with the flashlight.
On the flashlight, sometimes it's cool to add a "snoot". I make one out of some black poster board, roll a small bit of it up into a cone and stick it onto the end of the flashlight. This makes the light more direct and concentrated so you can direct it better and you won't have so much "spill".
There is no right or wrong way. It's all about doing something different. I took 62 shots. Around 8 were worth keeping.
I experiment like that as well sometimes.
But sometimes it just comes out looking all wrong...


Yeah, I had a lot of experiments that had to go back to the drawing board, too. 




