Don't Bluff Pot Committed Opponents
If you want to bluff someone who already has most of their chips invested in a pot, you will likely not be able to scare them away with a big raise. For example, in a pot where my opponent has invested 500 chips and he only has 100 chips left, putting them all in will not likely make them fold unless they have absolutely nothing and they just tried to pull a bluff on you. I would say that 90% of players call if they are pot committed, even when they don’t have the greatest hand. Don’t bother bluffing under those circumstances.