Leaving a very secure, high-level advertising job with a big corner office at an established agency to start a new company was definitely a make or break moment in my career. I had worked my tail off to become the company’s youngest-ever EVP. Things were going really well. Why would I walk away now? But that’s the thing about make or break moments: you often don’t see them coming. I certainly didn’t. I had a young child, a husband who had just started a new job, and a successful career. But then I received a phone call from Linda Kaplan Thaler, the chief creative officer of a competitor ad agency. We shared a highly successful client: Clairol.

After Linda’s agency was forced to resign the Clairol business because of a perceived conflict of interest, Steve Sadove, then CEO of Clairol, suggested Linda and I join forces. Over breakfast in 1997, Linda and I created the Kaplan Thaler Group. Clairol was our first client. Colaborating with Linda was the hardest and easiest decision I had ever made until that point in my life. I had absolutely no safety net. If this didn’t work out, I was out of a job. And while that was a scary realization, I also knew in my gut I could make this startup agency work if I relied on my guts, resilience, and tenacity–my grit–to make it work.

And it did work–brilliantly so. The Kaplan Thaler Group went on to become the fastest growing advertising company in the country. Now known as Publicis Kaplan Thaler, it is one of the top-ten agencies in the world. This experience prepared me to take another huge leap seventeen years later. I decided to leave advertising and New York to become the CEO of Legacy. As I sit in Washington, D.C. today working to end the number one preventable cause of death in the U.S–smoking–I can confidently say that taking risks is often the best way to advance your career. Here’s how to turn a make or break moment into a success:

Prepare for the worst
Mentally fire yourself. Ask yourself what you’d do if you lost your job today. Make a list of the steps you would take. This will help reduce the shock (if it actually happens) because you will already have a backup plan created. In the same respect, this could also help you decide if you’re ready to take a risk in your career. If the worst case scenario really isn’t all that terrifying, it may be time to take a chance somewhere else.

Don’t make excuses
The next time you make an excuse for something you didn’t do–or you did poorly–turn the excuse into a question. What could you do differently next time? Recognize your mistakes and commit to making a change.

Make yourself uncomfortable
Get out of your comfort zone. According to research by the University College of London the brain craves novelty. So doing things that don’t feel routine can have a positive effect on neurological activity. Trying new things will keep the creative juices flowing, and ultimately lead to better decisions.

Read all answers to the MPW Insider question: Describe one make or break moment in your career–how did you navigate it?

3 questions to ask yourself before accepting a job offer by Donna Wiederkehr, CMO of Dentsu Aegis Network.

3 lessons executives can learn from athletes by Pascale Witz, executive vice president of Global Divisions at Sanofi.

Why I quit my job to start my own business by Gay Gaddis, CEO and founder of T3.

Ex-Oracle executive: How to take smart risks at work by Liz Wiseman, president of Wiseman Group.

Build-A-Bear CEO: How to navigate difficult career decisions by Sharon Price John, CEO of Build-A-Bear Workshop.

Why I gave up everything to start a career in Singapore by Perry Yeatman, CEO of Perry Yeatman Global Partners.

Why I choose to put my children before my work by Lauren Stiller Rikleen, president of Rikleen Institute for Strategic Leadership.

How this Google executive handles stress at work by Margo Georgiadis, president of Americas Operations at Google.