I listened to Bart Hansen's interview of Ed Miller on my podcast walk during lunch today. As Hansen is primarily an LA player, and Miller plays mostly in Las Vegas, it was interesting to hear the two discuss the differences in player types and styles between the two cities. Because people tend to play for different reasons in the two locales (e.g., there are more serious poker playing tourists in LV), there is a marked difference between the play of amateurs in LV vs. LA. There was one area, however, that Hansen and Miller seem to agree was common: player mistake types.
Miller said that in his opinion, there are basically two types of amateurs he plays against in mid-stakes cash games: Those who make calling mistakes, and those that make folding mistakes. In other words, you can forget worrying about lots of nuanced differences; instead, just focus on whether your opponent (assuming he or she isn't a reg/pro) makes calling or folding mistakes.
If the opponent folds too easily (e.g., plays fit-or-fold poker), then you should raise them preflop, and then take away the pot postflop. Two thirds of the time they will miss the flop, then be afraid of continuing against the range that your preflop aggression implies you have, and then fold. Even if they connect to the flop, they will often fold to multiple bluff barrels if they feel their hand isn't the near nuts.
On the other hand, if your opponent tends to make calling mistakes (read: calls down too lightly) then the name of the game is value town. Don't bluff; bet for value and make them pay to see cards.
Hansen seemed to agree with this general simplification of reading player types. The main difference, however, was that he felt that the players he faces in Los Angeles tend to fall into the call-too-much category, while Miller felt that most amateurs in Vegas fell into the fold-too-much group.
Regardless, the main point both guys kept making was that you need to plan your hand ahead of time based on what types of mistakes and errors your opponents tend to make. Don't wait for the flop to figure out what your strategy is against player X; decide on it beforehand, and then start acting according to maximize your EV given that type of mistake.
All-in for now...