In today's tournament, I am in a good situation (7000 chips when the average is just 4000). Next hand, I got a pocket pair (J, J) but someone before me have a pot size raise. I went all-in, but found out that he got a even big pair (K, K). Then my situation suddenly went bad (from 7000 chips to 2000 chips).
When you got a premium pocket pair (>10), see what's your stack
If your stack is small, then just go all-in to see if you can survive;
If your stack is big, think more:
estimate the stack size of the player (raisers before you and players after you) as well as the style of the player. If their stack sizes are much smaller than you and they are timid, all-in is preferred.
If there are players whose stack is similar to you, don't risk all your chips, reraise to test them and if they reraise it again, you got more information.