3 Leadership Lessons From the Exclusive Creativity School That 'Packs 5 Years of Learning Into 5 Days' Christina Miller, a Cannes Lions School alumna and the head of social media at VMLY&R London, shares the biggest lessons she learned during her time in the program.

What does it take to be a real leader? It's a question that can be as confusing as it is exciting to explore, and it's an essential one too: We all know that leaders can make or break a company's long-term growth and success. Being a strong leader requires you to cultivate some important skill sets and strategies — and learning from those who have already made it to the top is a surefire way to do it.

Enter the Cannes Lions School, home to the four LIONS Academies: Roger Hatchuel Student Academy, Creative Academy, Brand Marketers Academy and Media Academy. The Academies offer the next generation of professionals an opportunity to learn from industry experts and grow as leaders in their chosen fields. According to former global chief creative officer of Leo Burnett Worldwide Mark Tutssel, the school gives students the chance to experience "five years learning in five days."

The Cannes Lions School is a component of the Cannes Lions International Festival of Creativity, which has been championing creative excellence since 1954 and runs from June 20-24 this year.

Related: 5 Brain Training Techniques to Cultivate Your Creative Genius

Entrepreneur asked Christina Miller, a Cannes Lions School alumna and the head of social media at VMLY&R London, to share some of the biggest lessons she learned during her time in the program. Here's what she had to say.

Put in the work to get the best results

"You only get out what you put in," Miller says, adding that she learned that lesson the hard way.

At the beginning of the Academy, Miller had to miss some of the program's sessions because she was attending award ceremonies. She explains that although the Academy doesn't force you to be present, of course, not showing up makes it that much harder to get all that you want out of the experience.

Once Miller was able to take full advantage of the program, it was easier to make critical connections and learn from amazing leaders from all over the world. "If I could do it again, I'd pour even more of my time and energy into showing up, connecting with my peers, and connecting with the leaders who volunteered their time to come speak to us," Miller says.

It's a straightforward, but incredibly pertinent, lesson in leadership that applies across roles and industries: Put in the time and effort to see the results you want to see.

Related: You've Got the Dreams But Are You Doing the Work?

Don't be afraid to speak up

It can be intimidating to voice your opinion to a group of executives, particularly if you're just starting out on your professional journey.

But Miller says Matt Jarvis of 72andSunny, one of the speakers during her time at LIONS, offered students some extremely helpful words of wisdom. "One thing he talked about that really resonated with a 28-year-old Christina was about not being afraid to have good ideas and share them just because you're junior," she says. "To quote him, 'Don't fear approaching your executive team with an idea on how to shake things up, because it'll be extremely welcomed.'"

Jarvis also spoke about it being lonely at the top, and he stressed that good ideas can come from anywhere. "He encouraged curiosity and confidence, which at the age we were all at in the Academy, was a message that was much appreciated and well-received," Miller says.

Even if you're just starting out in your career — and perhaps especially if you are — make your voice heard. You might just have the best idea in the room.

Related: 11 Women Leaders on How to Make Your Voice Heard

Find a mentor, and pay it forward

"Find a mentor, and be a mentor to someone else when the time comes," Miller says.

More and more people are realizing the power of mentorship. The research backs it up too: According to Harvard Business Review, people with mentors perform better, progress more quickly in their careers and experience higher work-life satisfaction.

Miller explains that in one of the LIONS sessions, a speaker discussed the importance of finding a mentor who can guide, validate and challenge your decisions, serving as an unbiased support system — a must-have in any industry. "She spoke about seeking out a mentor whom you look up to, and openly asking them to be your mentor," Miller says. "At the time, I was in my late 20s, and asking a senior level person to be my mentor felt uncomfortable, but it was some of the best advice I'd ever received.

"She also spoke of the importance of doing that in return for someone else in the future, and I look forward to the day when I can pay that back," Miller adds.

Not only can having a mentor help you advance in your career, but it can also give you the tools to help other emerging professionals do the same one day — perpetuating a cycle of learning and growth that's hard to replicate in other ways.