One thing I love about ASoIaF is that generally, people behave like a normal human would. Some think carefully about what they should do but there are also MANY that think very stupidly. Whether they let honor, emotions, tradition, religion, or anything else get in the way, they will make one stupid mistake and it costs them everything.
The point of this thread is to portray yourself as someone in the books, whether they are a major character or a minor one, and alter what they would have done. Try and not bias your decision on knowing what happens in the books! Example being "I would have changed Robb's decision to not go back to the Twins." or something like that. Since he had no knowledge that he was going to be killed at the RW, at the time that was his best option (and also his worst since he married Jeyne.)
Me personally? I think the simplest answer would be to be Balon and change his plans for the Iron Islands. He talks about independence, and being the King of his own lands, or islands I should say, and all that. What does he do?
He plans on attack the OTHER house and people that wan't to be independent from the IT. He is blinded by not only tradition, the iron way, but also his emotions from losing his sons in the war from his first rebellion. He starts a rebellion, then gets pissy that people end up killing his sons. He started a war... did he think no one he cared about could possibly be killed? With his logic, shouldn't the families his sons killed also be able to take their revenge on his family or Theon and Asha?
He should have realized that his plan was flawed because it had no real direction. He was in between two different wants, and even if he had lived, he would have gotten nowhere. Hell at least Euron HAS a direction even if I think it will fail horribly.