One of the previous survivors of the Games, Haymitch Abernathy, served as her guide in training for and getting through the games. I modeled a few scenarios in Excel to convince myself of this, but I won't present those here.
Also, stay away from people you're physically attracted to. In other words, just by nature of the accumulating lottery entries as you age, one out of four lottery draws should be an 18 year old.
So does being active. Odds of living: This strategy is pretty good. Never underestimate the power of a daring dress. Similarly, when you're a startup company - especially in a hot industry - there's often a mad dash for fundraising, talent, and other resources.
Meanwhile, even the last, strongest Career has been voted off the island by a pack of mutant dogmonsters. She's pretty and likable enough to get enough to get presents from sponsors, but she was also as skilled with a weapon and smart enough to realize that people like a showmance romance on a TV show once in a while.
So a 12 year old is in a minimum of one time, a 13 year old is in a minimum of twice, etc. A lot of companies start off with lots of capital, but aren't able to pay their bills because they're saddled with overhead or they waste resources because they think they have plenty.