An interesting thing I have noticed online is say you have three people involved on a flop, you are the small blind with a hand something like JTs and the flop comes down with two 9s and a 3,say the pot is about $16, if you are going to run a bluff here a tactic that in my opinion works particularly against weak tight opposition is to bet $9, quite often subconsciously people will unknowingly or knowingly associate the 9 you bet with the 2 9s on the table and will fold hands better than yours. The corollary to this is when you want action don’t bet an amount that will strike fear into people like the figure 9 does here. The fact of the matter is quite often the bet amount that people make is actually associated with their cards particularly from the less experienced players. Beware of this tactic as shrewd players will pick up on it, but it can be nice little sneaky way of stealing pots when it works.