The old adage holds trust: Practice makes perfect. The problem is, there's a gloss to it that ignores what's really at the heart of practice: Imperfection.

To be sure, we love to talk about failure on the road to success. J.K. Rowling (among many other literary noteworthies) endured countless rejections from publishers until, finally, she landed a win. The CEOs who endured business flops on their way to success are legion. Did you know Bill Gates, for instance, started a business called Traf-O-Data before the world was introduced to Microsoft? I didn't either.

But failure is not what paved the way to the top for Tiffany Dufu, CEO of peer coaching company The Cru -- not exactly. Yes, there were failures. Dufu acknowledges that. There was something more to it, though -- more than failures as one-off happenstances. It was a full embrace of imperfection that enabled her to drop fear and shoot for the stars.

"I used to be someone who was terrified of ever dropping a ball," she told CNBC in a recent interview. That is, not fear of occasional failure, but fear of imperfection.

Here's how she turned it around:

"I basically reappropriated the term ["dropping the ball"]. For me, [it] means that I've gotten clear about what matters most to Tiffany. I've figured out my highest and best use for achieving what matters most. I figured out, how do I meaningfully engage other people? How do I ask for help when I'm somebody who wants to appear as if I have it all together? How do I develop the vulnerability? That whole process is what I call dropping the ball. It's about releasing unrealistic expectations in order for us to all create lives that we're passionate about."

There are two key points worth calling out for up-and-coming CEOs -- many of whom lean to much into perfectionism.

1: Meaningfully engaging other people requires vulnerability. 

Vulnerability means admitting imperfection. That admission opens the doors to others' admission, which drops unnecessary barriers and allows passion and skills to take the fore. It also engenders trust, which makes relationships -- and progress -- stronger.

2: Setting realistic expectations starts with those at the top.

 If you unrealistically expect perfection of yourself, this pressure will cascade down to your employees. Fear of failure will be constant, which saps energy best spent on focused work and innovation.

At the center of all of this is passion. The success that Dufu has seen is not merely the product of hard work -- though that investment is apparent. It's about being free enough to feel and act on genuine passion. That is what makes waves. 

As a note of support for all of those struggling with (im)perfection, Dufu adds: "I wish that I had known that all of the things that I was insecure about would become my superpower. ... [These are now the] important parts of who I am and my livelihood."

Wise words for anyone in leadership -- and powerful enough to become a daily mantra.