Bluff it or dump it. KNOW YOUR OPPONENT.

If the other player isn't a calling station and the board looks like one I can bluff against and I have 1 or 2 callers I'll quite often take a stab here, particulary in position where I can often get a "free" river card if I miss the turn and it's checked to me again.

Figuring out if I raised with AA, KK, QQ or AK, AQ, KQ is their problem, not mine.