Krawcheck, who held executive roles at Citigroup and Bank of America before co-founding female-focused investment platform Ellevest, says her time on Wall Street cultivated her negotiation skills, adding that “if you weren’t standing up for yourself, you knew you were losing ground.”

While she’s a seasoned negotiator by now, the CEO recognizes that talking salary is never easy—especially for women. On average, women are less likely to negotiate their salary than their male counterparts, often because they lack confidence or guidance. Aside from leaving money on the table, that hesitation is a reason—at least in part—that the gender wage gap still exists.

Here are three of the most common negotiation mistakes women make, according to Krawcheck.

1. Assuming there’s no room for negotiation

The first (and biggest) mistake that women make is not negotiating because “we take whatever first offer we’re given, assuming that’s the final offer,” she says. In other words, women tend to assume that once they’re given an initial offer, it’s a yes or no answer.

Krawcheck suggests negotiating a 5% to 10% increase on the initial salary you’re offered. But if your potential employer won’t budge on the dollar figure, try negotiating something else. For example: If you think learning how to code would make you a stronger asset to the company, ask if your employer would be willing to pay for a coding class. And if the company won’t pay for it? Ask for time off to take the class.

2. Worrying about a socially awkward situation

Women typically avoid negotiation because doing so can present a socially awkward situation—a phenomenon called the “social cost of negotiation.” Krawcheck notes that the fear isn’t surprising, especially since, as women, “we are socialized to have people like us,” As Reshma Saujani, founder and CEO of Girls Who Code, said in a 2016 TED Talk: “Boys are taught to be brave, and girls are taught to be perfect.”

Krawcheck says she still gets nervous during negotiations. “It’s the tension of that tough, interpersonal conversation that makes my neck flush.” But being temporarily uncomfortable isn’t worth leaving money on the table, she says. “It’s easy for us to skip asking for the money because it’s tough, stressful, and painful,” she says. “But if you’re not winning, you’re losing.”

3. Not practicing in advance

As the saying goes, practice makes perfect. “Practice [negotiating] with a roommate, with a significant other, or with your parents,” Krawcheck advises. The key is to remain calm and avoiding any sort of an emotional appeal. In other words: Focus on your value to the company, or how you’ll make the company better—not on personal reasons. To build confidence, it’s also important to practice having someone push back against your counteroffer, she adds.

Another helpful tactic is to pretend you’re negotiating on someone else’s behalf. One Tel Aviv University study found that women achieve better results when they’re negotiating with or on behalf of friends.

“We should be able to be paid the amount we should be, but until we change the world—this is the way it is,” she says.