Painting with light is a fun technique that gives great results. It is called painting with light because this is what you are actually doing while taking the shot - painting with light.
It is not needed an expensive camera, a camera capable of long exposures is more than enough. This series was shoot with a film camera (Nikon FM10) but if you really want to get the most out of the shooting session, use a digital camera. You will be able to see the results in "real time" and make corrections as you go.
You will need too a tripod or a place where to put your camera and this stays still. A flash light or torch, color gels or color cellophane (this is cheaper). And dark location, some of these photos were taken outdoors during nights without moon.
If you do not have an external lightmeter, point your torch to your subject, get your camera and aim it close to the spot light and made a reading of the light. It will likely tell you something like 2.8f, 1/4 sec, but if you want to play with different colors you will need a longer exposure, so for 15 seconds you will need an aperture of f.16. So 15 seconds for one color in one side of the subject and other 15 for other color in the other side (like the photo of the man's head in red and blue) so a total of 30 seconds, plus 10 of changing gels let's make an average of 45 seconds at f.16
After you set your exposure start with one color first, lets see the horizontal photo of the lovers, you see two colors, yellow and red. In this case I started with the yellow gel and moving the spot light up and down so the light will be uniform on the lovers, once I finished with the yellow, I turn off the torch change gels and turn it on but now pointing to the background. Because I did these photos on a mechanical camera I used to set it up in bulb and once finished I stop it.
There are no limits for this technique, start playing around and you will be surprised with what you will get.