Okay, I'm assuming you're talking tournaments, since otherwise you don't have to be short.
Once you get to be shortstacked (I define this as an M=<5), the cards aren't even what's important anymore. It's nice to have something to fall back on, but you're just looking for an opportunity where it's been folded to you, and you can open-shove while you still have fold equity.
Your goal as a shortstack is to take down the blinds + antes without a fight. As long as you have any FE, then the cards don't matter, because most of the time, your shove will win the pot. If you've just shoved a few times recently, then you need to pull back on the reigns a bit, and understand the flow of your table, and how players are going to react to your play. Obviously, this makes it an ideal time to shove again if you pick up a legitimate hand, as your opponent's call-shove ranges have widened significantly against you now.
You want to be thinking ninja here, sneak in, take the money, and you're gone, before anyone even realized what happend.
Not Marine, running in, blowing ***t up, screaming and shooting. You don't survive in tournament poker by picking fights against bigger stacks.
Once you're desperate start to look more at the situation, and if you think you can win the pot with an all-in here. If you likely can, then do it, and don't worry about what your cards are. They won't matter very often.