Jay Leno made a name for himself as host of NBC's "The Tonight Show," a position he held for 22 years. It also earned him a fortune: The gig reportedly paid as much as $30 million a year. But before his massive success, Leno started his career at McDonald's, earning minimum wage at a joint in Andover, Massachusetts. Here are five things the self-made millionaire did that helped catapult him to success.

1. He worked multiple jobs

The comedian didn't experience overnight success — "I wasn't a millionaire when I started," he tells CNBC Make It — but he discovered the key to getting rich early on: Developing multiple streams of income. From the moment Leno entered the working world, he always had at least two ways to make money: "I had two jobs because I realized that was the quickest way to become a millionaire."

2. He saved his bigger paycheck

Leno was smart about how he handled both paychecks, too. He banked the bigger one and lived off the smaller one. When he was first starting out, that meant saving the money he made working at a car dealership and spending what he made as a comedian. "Then I got to the point where the comedy money was, like, five times the other money, so I decided to flip it around and save the comedy money," Leno says. "I would always spend the lesser amount of what the two were."

He continued relying on this strategy even after he started hosting "The Tonight Show" in 1992. "I pretended as if I didn't even have the 'Tonight Show' job," says Leno, who instead, lived off the money he earned doing comedy gigs on the side. "You know, when you start making money, you get lazy. I wanted to make sure I always had that hunger, so I never looked" at his TV money. "It would go directly into a bank." After 22 years on the job, he accumulated "a nice little nest egg," he adds. Even today, Leno still does two to three comedy gigs a week, or "210 jobs a year outside of whatever else I'm doing." After all, "if you do something and it works, then keep doing it."

3. He avoided credit cards

The self-made millionaire has never liked the feeling of owing anybody anything. Even today, "I barely use credit cards," he says. "I don't carry any debt. I don't write checks at the end of the month for anything." And that includes a mortgage, Leno adds: "I didn't buy my house until I had cash. When you own something and you don't have to write checks every month, you're just better off." His conservative money philosophy helped him build a fortune and it continues to give him peace of mind. "I own everything. I own my buildings. I own my cars. That way, if it ends tomorrow, I know what I've got," Leno says. "It's a little old fashioned, I suppose, but it seems to work pretty well for me."

4. He set high standards

It was actually while working at McDonald's when Leno first learned a key pillar of success: You can never go too far to ensure you're producing a great product. Throughout his career, the comedian has held high standards. After finishing episodes of "The Tonight Show," Leno would head home and continue writing jokes, according to a 1993 profile by CBS's "60 Minutes." He and his staff would go through hundreds of jokes before whittling the set down to the best 20. Then, Leno would read the jokes in order into a tape recorder, re-listen to them and determine the exact wording and timing for each one. "I meet with the writers at about midnight or so and work until about 4:00 a.m.," Leno told "60 Minutes." "I sleep four hours, maybe five." The way he saw it was, "if you have time to complain, you don't have enough work to do."

Tonight Show host Jay Leno during 'Headlines' segment on June 8, 1992 . NBC | Getty Image

5. He embraced mistakes