It all depends on what kind of scheme/strategy you're defending. There really isn't a cover all blitz strategy because offensive game plans not only change from team to team, but from game-game and series-series. You also have to be aware of what kind of defensive talent you have, if you're DL is matched up well and getting pressure you may not even need to blitz.
I have been playing a bend-don't-break scheme in my current dynasty, simply because my secondary is terrible. I was bringing heavy pressure in my first couple games, but I kept getting burned. Now I basically play basic zones and wait for the offense to make a mistake. I do start blitzing heavily in the red zone, so even if I do get drive down the field I limit them to a FG most days. I hate playing defense like that, but I don't have a choice; I would slow people down with the blitzes, but end up giving up 2-3 long bombs a game. I give up more yards with my current strategy, but fewer points. This works well with my offense also, given the amount I throw the ball. They can keep me off of the field all they want; I can score quickly.