How to close an MTT?

Hey,

in my last 15 MTT's I have 3 FT's and 9 cashes, I often end up being in the top 10 for most of these but eventually the average/antes/blinds catch up to me, I do my best as far as stealing when possible but often face strong opposition to my steals, as a rule I try to steal only with decent hands but nothing I can call the subsequent all ins with (and they are a constant) it comes to the point where blinds are so high that a steal will cost 14th or 5th of my stack and I am often top 5 in this situation.

Someone drop a jewel of knowledge on me

Thx