Something very important that nobody has mentioned yet is position - it's all about position! If you are going to bluff at a pot, it's best to get a look at what everyone else has done when the flop comes. If someone comes out and bets strong, lay it down. If it checks around, there is a good opportunity to take a stab at it with a 3/4 pot size bet.

If someont comes out and bets weakly on the fop, consider raising them to about the size of the pot.. In this case, the read is very important though.. Does this guy like to weak lead? Don't do it. Is he a calling station? Don't do it. If you get called here, respect it unless you improve greatly on the turn.

Also consider the texture of the flop mixed with the PF action. If it was raised PF and there are still 3 or 4 people in the pot, don't try to represent the A,K, or Q - someone has it.

If you typically have a lot of community pots, perhaps you should be raising more PF to thin the herd.