Bluffing is not a requirement in no limit texas hold em. It is simply a tool you have in your box that you can use (along with other tools) in order to gain money. If the board flops three diamonds you could put in a bet to represent a nut flush draw even though you hold two black clubs. If you flop bottom pair WITH an open ended straight draw, you could put in a semi-bluff and bet out hoping your weak hand turns into a much stronger hand.
It all depends on the situation, your playing style and the playing style of your opponents. If you are playing against tight opponents with big starting hand requirements, you can bluff more pre flop. If you are on a loose table with chips flying about like crazy, it is worthwhile to bluff less often. About 10% of your game should involve bluffing to some extent. If you wait around all day for a monster hand, it may never come. If you bluff all the time, you will soon not get any respect for your raises and will get far too many players entering a pot with you.
A good tip is to look at your watch when you are dealt your hole cards. If the second hand is between 00 and 05 seconds and your position is late (the later the better) then go for a bluff this round if the situation warrants it. Clearly if there is a raise and a re-raise, then do not get involved with junk!