For new carpet I always place 2" white tape, press it down as going along, and where possible, in the same way mentioned in post #4. IMO white tape adheres better, and when removed, causes the fibers to raise up a bit, which 'hides' the unpainted part of some hard-to-paint-all-way-down baseboards.
I usually tape the carpet before rolling the ceiling and walls, for another reason: accidental paint spatter on the carpet from the rolling and cutting-in, as the tarps do not always stay close to, and at times tend to move away from, the baseboards.
Btw, good business tip, Z.

I think it's more effective than simply placing an ad in the paper and waiting..