I think he is asking how do you bluff when you shouldn't.
That's what I thought at first. I'm not sure that's the case though. The question was worded... in a non-optimal manner.
I recommend buying and reading
Harrington on Hold'em Volume II (after reading
Volume I of course), as it deals a lot with this sort of topic.
Basically bluff the middle stacks, because desperate short-stacks and comfortable big-stacks are liable to fight back.
If you are getting short stacked, your move depends on your M and the action proceeding you in the hand. With an M at around 5, you can shove with just about two cards as long as nobody has voluntarily put chips into the pot yet.
Basically, you need to make big moves (and steal or get lucky)
before you get too short stacked. If you're too short, people will call you with anything because losing to you isn't painful, and even if you do double up you don't win much.