The 2 go-to questions this millennial millionaire asks himself before paying for anything

The last movie that Todd Baldwin saw in theaters was Star Wars: The Rise of Skywalker.

While he is a big enough fan of the Star Wars franchise that he says he would have paid to see it, Baldwin managed to not only get his tickets fully reimbursed, but he also made $100 thanks to his side gig as a secret shopper.

The 28-year-old is a self-made millionaire, thanks in part to some smart real estate investments. But he still thinks about every purchase he makes and doesn't hit the "buy" button on just anything.

While Baldwin may have more money than the average 20-something, he tells CNBC Select that he always asks himself these two questions before spending money:

1. Can I somehow get it for free?
2. Can I get paid to do that something or go to that place?

Baldwin has been asking himself these two questions since his college days, when he couldn't afford to take his then-girlfriend (now wife) out to dinner, so he searched on Google for "how to get food for free."

The search results led him to try secret shopping, which essentially entails Baldwin visiting restaurants, movie theaters and other businesses, posing as a normal customer. When he returns home, he fills out a survey about the food or customer service. He then gets reimbursed for whatever he purchased during his experience, plus sometimes profit on top.

Baldwin estimates that he's probably made about $30,000 over five years of being a secret shopper. He once got paid to stay at a hotel with a casino, where he got the room and food for free, as well as a $300 gambling credit. He ended up winning $1,500 that weekend.

But for Baldwin, the secret shopping is more than just about the profit. It also saves him a lot of money. "It's definitely a way to help save because I don't spend money on food and drinks," he says.

Baldwin says he has a frugal mentality, and over the years, he's taken the money that he would have spent on food and entertainment and put it toward building an emergency fund and other nest eggs in his multiple high-yield savings accounts.

While he chases the highest-earning yields when choosing his next savings account, putting the bulk of his extra cash into the account that pays the most, Baldwin encourages others to find the right account for their needs if they're looking to save. Even $20 per week can add up quickly when you're first starting out — consistency is key.

If you want to do your banking all in one place, consider opening an Ally Online Savings Account, which offers customers both a checking and savings account. The account also comes with zero monthly maintenance fees and no minimum balance or deposit requirements.

For those savers looking for a higher return on their money and extra help saving, consider the Varo Savings Account. The online bank offers two programs that automatically transfer money from your Varo bank account to your savings account: Save Your Pay, which transfers a percentage of your paycheck into your savings, and Save Your Change, which rounds up your checking account transactions to the nearest dollar and transfers the difference to your savings.

Whether you earn extra cash by using Baldwin's spending technique or you have your own way of saving money, make sure you stash that cash appropriately.

Choose a high-yield savings account that offers safety and security in the form of FDIC insurance. Using one over a traditional savings account will also give you the opportunity to grow your finances much quicker over time.