Not necessarily rich, but there are active financial decisions you can make that will set you on the path to longterm prosperity. Buying a house at what happened to be exactly the right time and making a $100,000 in 3 years in the process is not one of them. That's just dumb luck.
I mean, "consistently save in a diversified portfolio" would be a pretty boring answer, but it would be an answer I guess. I'm not sure what the equivalent for the poor would be; stay away from substances, maybe?