If no flush draw on board, (2 cards same suit), I'd lead out with a bet of approx 1/2 to full size of the pot, depending on my read on the guy. If he calls or reraises, he most likely had the board beat, in which case I'd fold to the reraise, or check the turn if I miss that too. If he missed the flop and is either on a draw or hoping to hit an overcard, that size bet should get him to fold a fair amount of the time. That's my way of doing it, which could change tomorrow...:-)