I am not a UHNW guy, but here's my 2 cents.
About getting there, we all read about people who get there, either by hook or by crook, and there seems to be many different ways. I myself tried by working hard for some years at a couple of startups that I helped found along with friends, and they both went belly up. Good thing I put none of my own money into it.
So, I got old and too tired to try anymore. Just counting my money in the market now, and I am glad I have enough to live comfortably. So, from my own experience, one is either lucky, or knows how to do it, or he doesn't. I belong in the last group.
That's the extent of my knowledge and experience about trying to get there.
About how much and what to spend money on once you get there, I think that is quite easy to learn. Other people will be glad to show you how. Spending lots of money is a skill too easily acquired. The hard part is not to let it become an addiction.
It appears that people who work hard to get their money tend to value it more and spend more judiciously. And their fortune stays intact. People who get the money falling from the sky tend to squander it fairly quickly, and they don't have that trouble of figuring how to spend that money anymore when they no longer have it.
Again, that's from observations, and not personal experience.