Strategies for Multi-Table Tournaments?

[caretaker1]

Hello,

I'm looking for some advice from experienced multi-table tournament players.

First, what do you notice that separates good tourney players from bad ones? In my tourney experience, I tend to play fairly tight early, however I either end up getting blinded, or, if I get a few hands, I get fairly deep into a tournament, but not usually better than top 50 or so (out of 800 or so).

I've noticed some players get a big stack and then wield it mercilessly:
Can aggression alone be sufficient to get in that position? In other words, can you get there without a run of premium hands?
When do you pull back on the aggression throttle?
What do you look for in the big stack when preparing to "bully" the table? Thank you in advance.