Ideas/Strategies to get to the Final Table

[Supersetoy]

So I've been playing the MTTs on Stars (lower buy-in, $10 and $20) for the past month now, trying to get the hang of them.

I've been getting deep in to them, but for some reason, bust within 1-2 tables of the final table (20th last night, 32nd the night before that, 25th over this past weekend, average of 450 entrants).

I understand how to build my chip stack on the bubble, when to steal in position, and I try to be in the top 30 throughout the entire tournament. When it gets down ~30 people, I'm right around the average, if not a little higher, yet somehow I end up busting in 20th-25th.

Any ideas/strategies on how to get past this and on to where the real money is? It's quite frustrating walking away +$50 for 4 hours of play. Thanks in advance.

(Surfed through the "wisdom" sticky and didn't see this issue addressed)