Depends on the situation. Are we heads up, is it multiway? What's your position, who has the lead with the betting, (who made the last raise).
Ask yourself why do we bluff too? Is it to win the pot there and then, is it to semi-bluff, is it to find out where we are..just incase your bluff isn't really a bluff, it's possible your opponent missed the flop too.
As an example where I would maybe bluff is in position, heads up, with the lead. I miss the flop, but firing a continuation bet in my opinion is almost certainly the best option no matter what the flop is. It forces your opponent to think about ther move. You're the preflop aggressor and could win the pot there and then.
If you checked in this position, VILLIAN could raise and you are almost forced to fold. If he checks then you have given him a free card to improve his hand.
So every situation is different.
Hope this somewhat helps