Jill Schlesinger got her start on Wall Street, and now reports on business for CBS News, hosts a national weekly radio program on personal finance and writes a syndicated newspaper column.

In her new book, "The Dumb Things Smart People Do with Their Money" (Ballantine Books), she lays out 13 of the most costly blunders people make. One of her prime candidates for potential danger is buying complex or expensive financial products like variable annuities, precious metals and reverse mortgages.

I spoke with Schlesinger recently about the big errors people continue to make when it comes to saving and investing for retirement.

Q: One of the fun things about your book is your own money confessions. A big one was your failure to time the market during the early 2000s as the stock market was starting to recover from the dot-com bust — you write that you were slow to invest in riskier growth companies, which cost you a good bit of money as the market came back. But the real lesson is the futility of trying to time the market, right?

A: I used to think that I understood highs and lows better than the vast majority of the investing world. And during the early 2000s, I was basking in the glow of my decision to partially sell out of fast-growth tech stocks at the height of the bubble. But when the market started to recover in 2002, I waited way too long to get back in, and wound up with a lot of egg on my face.

When you have a public persona like I do, you can really start to believe your own baloney — and it can be really difficult to get back into the market at the right time.

Q: What's the big lesson here — everyone should be passive investors?

A: Right. Maintain a diversified portfolio, with the allocation between stocks, bonds, cash and so on set according to match the time when you will need the money. Take as little risk as possible to reach your goals. No one is smart enough to beat the market — no one.

Q: Another thing I like about your book is your discussion of first priorities — things people can do to clean up their financial affairs without the help of a planner.

A: Start by paying down consumer debt and establish an emergency reserve fund to cover six to 12 months of expenses. Then, put enough into your retirement account to capture any match from your employer. I used to be more severe on this point, advising people not to save a single dollar until their credit cards were paid off. But I've softened up a bit on that, because if you can get in the habit of saving, you should.

Mark Miller writes for Reuters.