I generally never show my cards. If I do, it is because I sometimes show what I folded after the action is over. I don't do this often, but I do it sometimes. I might show an AA if everyone folds to me, but only because it is funny that it didn't get any action. I very rarely show bluffs, because if I am playing bluffs that hit, I am already forced to show those at showdown anyway. And that's enough for players to know I will bluff sometimes. I don't want to add more to their perceived stats on me. I might do it though if I need to create a perception on me at a certain table, where that could work to my advantage somehow, but this too would be rare.