From my experience at the low levels where players are extremely weak you don't need to bluff to make a profit.

Bluffs work best when you are against tight players who play a bet(when they hit) or fold strategy(when they miss). When you move up levels the bluff becomes much more important against the trickier players and you may find that you need to delay your contuation bet.

If you go to cardplayer.com look in their articles archives there's some good stuff about when to bluff.