Think about it....if this was an easy question to answer, wouldn't we all just go out and do it? The truth is that very very very few people ever attain the kind of riches you're talking about, and many of them are born into wealth that was amassed across a few generations.
And many come from quite humble beginnings.
It is an easy question to answer: you go where the money is. Period.
Of all factors said to differentiate those who accumulate wealth from those who don't, such as ethics or morality (I'm poor, but at least I can sleep at night), privilege (he inherited it or his family was wealthy), and nepotism (its not what you know but who you know), the only factor which is substantially true across the board and without considerable exception is attitude.
What sets the wealthy apart from others, excepting those who inherit their wealth, I'm referring to those who generate or earn their wealth from humble beginnings, is that they do not believe wealth comes to you. You have to go where the money is - where ever that may be - and earn it.
Many people are of the unworkable belief that they are the center of the universe and therefore the money should come to them. I've worked with dozens of these types over the years. This is the equivalent of believing employers should come knocking on your door instead of you knocking on theirs.
There is no serious money in turning lug nuts on an assembly line, or asking "Do you want fries with that?", or driving a delivery truck, being a nurse, or [insert any number of high supply/low demand jobs here]. Therefore, don't pursue any of those things, if generating wealth is important to you.
You pursue those things that pay what you desire to be paid and avoid those things which do not. Those who will remain poor or will never generate substantial wealth say they want to make more money, but will never do anything to make that happen except sit around complaining about it, with the possible exception of forming a union and forcing their employer to pay them what they desire to be paid (making the money come to them vs. them going where the money is).
This mentality is prevalent throughout society, as indicated by obese people who sit around 'wishing' to be thin but never getting their fat ass off the couch and into the gym. Or, someone who wants to have a muscular physique, but won't get their ass off the couch and into the gym.
People want the 'upsides' of some thing they don't have, but don't want any of the 'downsides' necessary in achieving it. The fat person who sits around complaining about being fat wants the 'upsides' of being thin, but wants no part of the 'downsides' of getting there (hard work, getting off the couch, letting go of the crutch they find in food, changing their lifestyle).
There are many other examples of what differentiates those who go out and get what they want vs. those who sit around wishing it would just fall out of the sky, but you get the idea.