I couldn't really keep crouching around on the ground like a monkey forever. Aside from the various injuries I was beginning to suffer in my neck and back, painting large pieces that way was just impractical. I've always tried to stay within my current limitations until it's absolutely necessary to break out of them. In fact, I painted with only house paint on crappy canvases for a long time until I finally felt ready to "graduate" to better materials. That was another handy tip from Ray Friesz, who's advice I realize now was crucial in getting me to paint anything to begin with. If I had purchased fancy paints and fancy equipment at the beginning, they would have sat in a corner until I felt prepared and educated enough to use them, which, of course, would have been never.
Not that I'm saying a piece of plywood set on top of an empty TV box is fancy equipment, mind you. But it's a start. Maybe one day I'll get a lamp too.