“You always have to think of yourself as You, Inc., even if you’re working full-time. What could you moonlight as and do full-blown later on?” says Kerry Hannon, author of What’s Next? Follow Your Passion and Find Your Dream Job. She recommends getting started three to five years before retirement, for financial as well as health reasons. “Unless you have a pension that’s turning out money, it’s nice to know you have a little money,” she says, adding that people who work longer tend to stay healthier as well.

Hannon recommends keeping start-up costs low and creating a new email address and social media presence that’s independent from any full-time work, to avoid potential conflicts of interest. “Create a separate identity yourself,” she says.

Read more at U.S. News & World Report.