I do bluff quite a lot. I don't when I have showdown value, I'll tend to play agro or passive depending on position and if I want a big or small pot. When villain shows weakness and I don't have sd value, I'll bluff mostly always, just the same as if I would value my hand. I would fold re-raises. When I get re-reraised often, I'll prepare a trap when I get a good hand, where I'll 3bet the street.
Big pots are so dangerous, and in small stacks where I do play, agro players tend to do not fold. I've been doing a lot of this msitake trying to bluff big pots with a high bet, which cost me a lot recently. I think that one must bluff not to win the pots when you bluff, but when you do raise when you have the nuts you get called, s you've been caught bluffing. Really not easy to do.