"you yourself should never bluff in a cash game"

"In low-limit cash games, I agree that bluffing is very limited "

I just don't agree. Pick your spots on a table where you feel comfortable with the way your opponents play, pay close attention to position, and go for it.

A fave of mine is bluffing in the cut-off: if you bet on the button, people often assume you're bluffing, but much less so if you're not in last position. This will usually force the button out, giving you both position AND giving more of an impression that you have a hand.