Depends on the stack sizes (side note to TWP - see I am learning). If the stacks are large enough and, based upon villains' play, I can expect to stack them (or take a sizable chunk)if they have AA or KK, then I call a 4xbb bet.
Set Mining 101 would say you should use the 5/10 rule. See Skeme's FAQ sticky
here for more details.
This is really an exercise in calculating implied odds. I will let the math wizards on this board explain further.
Damn - A monkey types faster than me!