At low stake games it is too difficult to bluff online as there are players who will just call anything. Maybe at higher stake games you can get away with it more.
Use only a bluff in the middle stages of MTT tournaments early because there is no sense to bluff, and in the late game is the principle of push / fold
I try to pick very carefully the spots whenever I wanna bluff either online or live. I just don't wanna go broke because of a bluff, I'd rather lose by an unlucky river or something not going my way.
when i smell weakness, i try to bluff but most generally if there's still hope for me in the pot. kinda semi bluff or if i sense the opposition is too weak or smt
I bluff online too but not if i holding nothing, mostliy with a A6 or so and 10 10 5 on the river.
So i have a really chance to win if im lucky and the other calls.