Manage your own money.

Kathleen Grace, a financial planner and author of “Prince Not So Charming,” says women often make the mistake of ceding control of their money to the men in their lives. Then, if they end up single later in life, as most do, as a result of either divorce or death, they’re not in a good position to take control of their finances. That’s why she recommends continuing to manage your own money, at every stage of life.