Don't buy a home because you think you should

If you can't afford to buy, don't stress. It's okay to rent, Orman says, especially if you live in a pricey city like San Francisco or New York. "I know a lot of you think the key to wealth is buying a home, paying it off and owning your own home outright," Orman says. However, "sometimes it makes sense to own a home. And sometimes, depending on where you live, it makes sense to simply rent." If you live in an expensive area, Orman suggests investing any extra cash in the market instead: "Whatever money you have freed up, that money is money you invest in the stock market — you get yourself out of debt, you keep dollar-cost averaging, you max out on your retirement accounts, then you have investment accounts and you just keep going and going and going." Eventually, you may have enough to buy something, or you may decide to pursue other financial goals. Other experts agree that, if you do want to buy, you should make sure you're buying for the right reasons. "Being smart with your money can look like living in an affordable rental and continuing to save and invest for future goals," Eric Roberge, a CFP and founder of Beyond Your Hammock, tells CNBC Make It.

Don't spend to impress other people

Orman doesn't believe in buying things in order to prove your worth to people you "don't know or like." It's a lesson she learned the hard way. "I will never, ever forget when I wanted to impress a girlfriend, this woman I was dating, who was seriously wealthy. She was far more wealthy than me at this time," Orman explains. "I didn't have money, so what did I do? I leased a BMW 750iL. "I went and I took money out of my 401(k) plan so I could buy a Cartier watch so I could impress her. I did every single thing that I am telling you not to do." Looking back, she called the experience "the most stupid thing I've ever done with money." "Not only did I not care about that woman, it was like, 'Oh my God, it cost me a fortune to do so!'" she says. "So take it from me, it's really not worth it."

Don't blindly trust your financial advisor

A financial advisor can help you get organized and make good decisions when it comes to money, but it's crucial to make sure that you're working with someone you trust. "In my opinion, if you have a good one, they're worth their weight in gold," Orman says. However, not all financial professionals perform to the same standards. "Don't think that they're always going to have your best interest at heart, because probably they have their own best interest at heart." You should always make sure your financial advisor is a fiduciary, which means they have a legal duty to act in your best interest as their client, like by steering you away from overpriced, risky investments you don't need. When vetting a new advisor, come prepared to ask questions, including, "How are you compensated for our working together?" and "What other services do you provide to me?"

Don't loan other people money