Making continuation bets out of position can be disastrous. You have no new information at all about your opponents and you're betting into the dark. In position you can throw your hand away to a bet if you'd like (saving money by making a continuation bet, getting raised or smooth called and then folding) or make a bet if it's checked to you. If you bet out at every flop then your more observant opponents will take notice and call you down with nothing. Check about a third of the time and bet 2/3 of the time and you'll get better results.

Also occasionally firing a second bullet after you're smooth called can take down a nice pot.