The 30 companies (and their young founders) on our 2017 list have been pulled and prodded, picked at, and pondered. And still they stand--thanks in large part to novel business models, in-demand products and services, and revenue to back them up. Indeed, these young firms represent the best of what this next generation has to offer.

But they have a long way to go. After all, every big business was small once. Here, we pulled together some of the best advice from this year's 30 Under 30 judges, who include: Real estate mogul and Shark Tank co-host Barbara Corcoran, XPrize's Peter Diamandis, Honest Tea co-founder Seth Goldman, CB Insights' CEO Anand Sanwal, and Uncharted Play founder (and 30 Under 30 alum) Jessica O. Matthews.

What is your best advice for young entrepreneurs today?

Barbara Corcoran: You should start your business when you're young. Experience is grossly overrated and there is no substitute for just jumping off a cliff and figuring out the answer on the way down.

What advice do you wish someone gave you when you were just starting out?

Peter Diamandis: First, find a mentor, someone you admire in the field you're most excited about and offer to work for that person for free. Think of it as a free graduate education. Going back a few centuries, apprenticeship was critical to one's success and I think the concept of apprenticeship is very valid again. Second, be clear about your passion and don't settle for anything else. Don't do something for the money or to make your parents or your teachers happy. Pursue a startup because it's your personal passion, your highest aspiration. If you do something you are passionate about, you will work harder than ever before and shine against anyone else. Doing anything big and bold is difficult, and if you're not totally in love with it, you'll give up before you succeed. For me, it was my passion for space, which I obtained during my childhood from the Apollo program and Star Trek. Space has been my primary motive force in nearly everything I've done. It's my guiding star.

What is the most common mistake you see young people make and how can they avoid it?

Seth Goldman: People think they need to take a certain job they might not like to help them get the next opportunity. But by agreeing to do something they might not like or might not believe in, they run the risk of either being good at something they don't like to do, or not doing well because they are unhappy--both of which are bad outcomes.

What is the biggest missed opportunity you're seeing today that would-be entrepreneurs should jump on?

Jessica O. Matthews: Would-be entrepreneurs should be looking at opportunities to optimize manufacturing and distribution. The way we get things to places has not really changed that much for hundreds of years, so there is room for disruption. There could also be more work done in material science, and trying to gain a better understanding of things that already exist naturally in the environment and of how to potentially make better use of them.

Where are you or what are you doing when you get your best ideas?

Diamandis: Historically, I've had my best ideas when reading a book. I view reading a book as a conversation with the author. For me, there were three books that made the biggest impact: The Spirit of St. Louis by Charles A. Lindbergh gave me the idea to start the XPrize Foundation. The Singularity Is Near by Ray Kurzweil gave me the idea to co-found Singularity University. I also suggest The Man Who Sold the Moon by Robert A. Heinlein, which gave me the idea for the Google Lunar XPrize and the work we're doing with Planetary Resources to prospect and mine asteroids. In addition to reading books, my best ideas have also come from brainstorm conversations with friends and colleagues I respect, who bring different perspectives to the table.

What book should be on every big-thinking entrepreneur's nightstand? Why?

Goldman: Aside from Mission in a Bottle: The Honest Guide to Doing Business Differently--and Succeeding, the book I wrote with my Honest Tea co-founder, I would encourage founders to read Jack London's The Call of the Wild. It helps remind us that we are all animals. And though we are often taught to suppress them, we all possess instincts, which can guide us on how to act and respond--and it's OK to trust them.

What's the one job interview question you always ask?

Corcoran: An interview question I always ask is, "Tell me about your mother?" Because an unhappy child rarely makes a good employee.

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