I received a copy of Digital Photographer magazine for Christmas, which contains an article on painting with light. I had heard of painting with light where an object is "painted" with a non-strobe light during a long exposure (see here). The article in this magazine however, discusses directly exposing the light source to the camera, so that the photographer can draw with it. After reading the article, I crudely wrote "Hi!" in my mom's living room, not revisiting the technique until today.
Witness lightman taking a leak in my bathroom.
Although admittedly only slightly less crude than my initial "Hi!", and by no means a work of art, this photo helped me understand some of the basics of light graffiti. It's really a matter of planning. I found it best to draw each line using only one stroke, and plan the order of the lines to minimize misalignment. For Lightman, I found the following order to work the best: head, arms (down), wee wee, torso (up), legs (down), pee, pee splashes. Initially I had done the arms near the end and had trouble aligning them with the head and torso (which were done first). Expect a future post on light graffiti when I can spend a bit more effort on creating an image which is pleasing as a whole.