You may be looking for an edge in your personal finances — something that can help you rethink your approach to money and start getting ahead financially. If so, you might benefit from hearing what billionaires have to say and learning from their experiences. So, here are a few lessons on frugality, investing, and generosity from some of the wealthiest people in the world.

1. Live simply and be frugal

Most people don’t associate billionaires with penny-pinching, but that’s how famed investor and billionaire Warren Buffett approaches his personal finances. Buffet bought a relatively modest house back in 1958 for just $31,000, which was around $275,000 in today’s dollars, and he continues to live in it to this day. For context, the median home price in July of this year was $313,700.

Buffett has summarized his views on success and happiness like this:

Success is really doing what you love and doing it well. It’s as simple as that. Really getting to do what you love to do everyday — that’s really the ultimate luxury … your standard of living is not equal to your cost of living.

Buffett also holds on to his vehicles for a long time, as does Wal-Mart founder Sam Walton. And IKEA founder and billionaire Ingvar Kamprad once shared why having lots of money doesn’t mean you should indulge yourself to no end:

I’m a bit tight with money, but so what? I look at the money I’m about to spend on myself and ask myself if IKEA’s customers can afford it…. I could regularly travel first class, but having money in abundance doesn’t seem like a good reason to waste it.