Smart investors don’t take long chances. They invest their money in probable situations — substantial businesses with futures that are all but guaranteed. Smart investors don’t shoot for the stars. Instead, they hope to beat the averages by hard work and common sense. But their objectives are realistic: getting 12% to 15% returns on stocks over the long term getting 4% to 6% ROI on bonds.

Wise investors understand that over a long period of time, you can expect the stock market to appreciate by an average of about 10% a year. For $10,000 to turn into a million at 10% ROI, you’d need to wait more than 50 years. If you don’t want to wait that long (and who does?) — and you don’t want to risk losing everything by getting into highly speculative investments (and you shouldn’t) — you have only one choice: You must increase the base of money you are investing. And the only way to do that is to increase your income.

Yesterday evening, I reviewed a financial plan put together for my sister-in-law. She has $400,000 to invest and was hoping to use the interest on that money to support herself. She also wants to be able to retire in 10 years. We talked about how much she’d need to have to retire. We agreed on $1.2 million. I explained that $400,000 appreciating at 10% (the historic average) would become $1.2 million in about 12 years, not 10 — but that’s assuming that every dollar is invested in the stock market. Her financial adviser recommended that she invest only 40% (or $160,000 of the $400,000) in the market. I think he’s right.

But since $240,000 of her money would be appreciating very slowly (say, at 4%) and since only $160,000 would be getting the benefit of a 10% yield, it would take her closer to 20 years to reach her goal. She wasn’t happy with that. “What can I do?” she asked, feeling a little deflated. “You have no choice,” I told her. “You have to increase your income.” We talked about how, working only a few hours a week, she could earn an extra $20,000 a year.

Other than quitting her job and getting another one at a much higher salary, the only possibilities that seemed viable had to do with part-time, freelance positions. For example, she can make that kind of extra money by working as a freelance graphic designer. At an average billing income of $60 an hour (and she’ll be able to charge more than that as her client list grows), she’ll make that $20,000 in 333 hours — or by working only about 6-1/2 hours per week. But wait. She’s going to have to pay taxes on her additional income.

So, we’ll bump her up to 415 hours a year, or 8 hours a week. That’s two hours a day Monday through Thursday, with Fridays and weekends off. If she finds that she loves her life as a freelance artist, quits her day job, and turns her second line of income into a business, she can easily make her million in less than seven years — and be retired with a comfortable income while she is still young enough to enjoy it. Investing wisely is an important part of wealth building. But face it: You won’t be able to turn a modest fortune into a great one in 10 years or less unless you find some way to bring in more money.