When putting together a business proposal, "It's less about rock-solid numbers and more about your idea and instincts," says Caterina Fake, the Flickr cofounder who now serves as chairman of Etsy. Be sure to research the competition, attend meet-ups, and pick the brains of friends who have been where you are now. Don't wait for outside funding to build a prototype, Fake advises. ("You need to show that you are already building a company.") Consider crowd-funding sites like Kickstarter — Fake is an investor — but be sure you know what you're getting into. Just because you love baking macaroons doesn't mean you'll love owning a bakery. "When you own the business, you're not sitting around with the beautiful smell of coconut wafting into your kitchen every day," Fake says. "Somebody else gets the joy of making the macaroons while you're in the back room dealing with lawyers and accountants." What kinds of companies does Fake invest in? "Ones that are about creativity and self-expression and making things," she says. "They bring people together in a soulful way."