If there hasn't been a raise, immediately push All in preflop if you have 9BB or less.
Even the best plans sometimes fail. Your chip count has dwindled, and to get back in the hunt for victory, you will need to make an All in move. The time to make this move is when you have 9BB or less. And you want to be the first aggressor in the hand.
Why with 9BB and not, say, 10?
With nine blinds, you get slightly better odds for this play. For example, if you raised 3x preflop and your opponent pushed all in, the ratio to call would be about 2.25 to 1.
If you have 10 blinds, in the same scenario, you get a 2 to 1 ratio.
And the reason you push All in instead of just raising is that you want to make it as difficult as possible for your opponents to call your bet. Also, you need to accumulate and increase your chip count, and doubling up in this spot is critically important if you still want to win.
Example:
You get a pair of pocket sevens. It's the early stage of the tournament. Blinds are 150-300, and you have 2400. Everyone folds to you in middle position. What should you do?
If you raise to 900 and any player calls, you are in an unenviable situation because you want to hit a set on the flop. If someone pushes All in, the pot will be 3750, and you will get a 2.5 to 1 ratio to call. You will have to call.
Therefore, it is better to push All in immediately. You will either win the blinds, more than double up, or be out of the tournament. Do not fear the risk.
Tip: Pushing All in from early position
When your chip count drops to 9BB or less, you need to risk everything until you are back in the blinds. If you have received terribly bad hands and are now in early position, your situation is even worse than it is now. Since there are more players left in the hand, there is a higher chance that an opponent will find a good enough hand to call.
It doesn't really matter what your opponents have; you simply must go All in. Don't just look for pairs, two face cards, or an ace. Include all suited connectors. Even if your hand is only slightly better than Q-6, you still must push All in.