When my family moved to New York City from London in 2000, we had two small children and were buying a house in the U.S. for the first time. We needed some financial advice. A friend recommended her investment adviser, who at the time worked at a big bank. We hit it off, and it was soon decided to put him in charge of managing our retirement savings.

I've been mostly satisfied with our choice, but now I realize it was more luck than skill. At the time, I had no idea what questions to ask to make sure this adviser would really handle our money responsibly. So if you're thinking about hiring someone to help you plan your retirement or improve your personal finances, here's what I've learned in the past 16 years.

First, some definitions of what can be over­whelming jargon: Financial adviser and financial planner are generic terms, often used inter­changeably. But certified financial planner (CFP) refers to someone who has passed exams on topics like taxes and retirement planning and is required to adhere to an ethical code. Meanwhile, a registered investment adviser (RIA) describes someone (or a firm) regulated by government securities agencies who gives advice about stocks, bonds, and mutual funds. Many such consultants are both RIAs and CFPs.

Second, the most important word you need to know when looking for financial help is fiduciary. That means the person you hire must put your interests before her own, instead of recommending investments that might increase her fees at your expense.

"Keep the word fiduciary in mind with anyone you talk to," says Doug Bellfy of Synergy Financial Planning, based in South Glastonbury, Connecti­cut. "Ask any potential adviser: 'Will you operate under fiduciary duty 100 percent of the time?' That one question cuts through a lot of this complexity."

In April, the federal government finalized rules requiring any financial adviser to act as a fiduciary for retirement planning. But if you're going to rely on an outsider to help you pick non­retirement invest­ments or make other financial decisions, you'll need to confirm that she'll act as a fiduciary in those areas, too, and disclose all potential conflicts of interest. Hence the reason to specify "100 percent of the time" in your question--and make sure you get the answer in writing.

Sometimes, financial advisers will promote investments that represent the best deal for the client, "and then take off their fiduciary hat and sell products that aren't in the client's best interest," says Kristin Rogers, an investment adviser representative with Garrett Investment Advisors, a national RIA.

Barbara Roper, director of investor protection at the Consumer Federation of America, suggests you ask any adviser you're thinking of hiring to sign a fiduciary oath, an example of which you can find on the website of the National Association of Personal Financial Advisors.

Next, consider how your adviser will be paid. Fee-only advisers earn fees solely from their clients, while fee-based advisers can also earn commissions or a share of revenue from third parties--like, say, the banks or brokerages that want to encourage advisers to sell their products. So hiring a fee-only adviser is the best way to reduce that kind of conflict of interest, says Roper. In that case, the fees can be set by the hour, by the project, or by a percentage of assets under management.

Depending on an adviser's experience and where in the country you live, the hourly rate runs between $150 and $400, Rogers says. If you want someone on retainer, expect to pay a percentage of the money you give her to manage.

For that, you can expect more than just invest­ment advice. Roper, for example, says she pays her adviser slightly less than 1 percent of her assets and in return gets help with all sorts of financial issues--from how to pay for a new car to "nagging me to get a will and reminding me that my son is now an adult and needs his own medical power of attorney."

From the October 2016 issue of Inc. magazine