The pot is a big consideration in your bluffs, because the size of your bluffs in relation to the pot in a lot of different situations will determine whether or not those bluffs can be successful. For example, if you are on the flop and are making a continuation pot, then your bluff should be between one half and two thirds the size of the pot, whereas if you are making a river bluff on the end you will either want to bet a suspiciously small or a suspiciously large amount in order to try and secure the pot. If you are playing against less skilled opponents who have no real reading skills but are knowledgeable about things like pot odds, then you will want to bet big and make it less profitable (or net negative) for them to call. These are all of the circumstances in which considerations about the pot come into play in bluffing.
In addition to pot considerations, timing considerations are also paramount when it comes to the bluff. When you bluff someone, what you are essentially doing is making it so that they can not call your bet either because of the size of your bet, the size of their stack or their lack of confidence in their hand (or in some cases a combination of the three or even all three). Having good timing in bluffs is being able to sense when one of those three factors is big in the mind of your opponent and then using that factor to push them around a little bit.
The size of your opponent's stack and the bet that they have to call relative to their stack is particularly a good way for you to time your bluffs right at the start and if you are playing in a tournament that is close to the money or in the money and slowly creeping upwards, the power of a big stack bluff increases dramatically. Greg Raymer, the 2004 World Series of Poker Champion, literally steamrolled over scores of opponents because of his aggressive play and he pulled off a number of successful bluffs specifically because he was able to masterfully exploit the differing stack sizes between him and most of his opponents.