They comprise one of the smallest fractions of the smallest and most selective branch of the United States military.

They spend an intensive thirteen weeks transforming America’s youthful suburbanites into the most respected and carefully trained elite warriors on the planet. They’ve earned their place among the nation’s finest leaders.

Their presence is commanding, their expectations are high, and their tolerance for excuses is non-existent.

Yet, they are not the uncompromising, foreboding, uncaring, staunch disciplinarians we’ve come to love being entertained by in the movies and on television.

They are Marine Corps drill instructors.

They are the premier leaders of their organization, and they are the backbone of the Marine Corps. Their mission is to write success stories. And, according to the Rand Corporation, the Marine Corps boasts the highest success and lowest attrition rates out of any of the other branch’s recruit training processes thanks to these professional and devoted leaders.

While the general perception of these Marines may suggest that they somehow possess larger-than-life superhuman characteristics, the truth is that they are carefully selected professionals who spend their lives and careers developing themselves into the leadership powerhouses that they are while on and off the drill field.

“Life isn’t about finding yourself. Life is about creating yourself.”—George Bernard Shaw

Meet Staff Sergeant Mary Phaly. She is currently serving a term as a drill instructor in San Diego. She is also among the first wave of drill instructors to serve in California’s Marine Corps Recruit Depot since the first female recruits to ever train in San Diego walked across the parade deck in 2021 making Marine Corps history.

Her drive, ambition, and acumen are enough to be sufficiently impressed and inspired. So, how does someone like Staff Sergeant Phaly develop herself into one of the nation’s best?

Here are 27 of her top personal development guideposts:

1. Ask for help when you need it. It’s not a vulnerability.
2. Learn your craft.
3. Learn your supervisor’s job.
4. Learn how every component of your organization functions and works together.
5. Set expectations clearly and be consistent.
6. Be instrumental and proactive in the success of others around you.
7. Know your people. Understand their unique learning styles.
8. Know your people’s values, beliefs, backgrounds, and goals.
9. Listen to understand always.
10. Keep yourself current and educated.
11. Be an effective communicator.
12. Be honest.
13. Teach your people how to think critically and become leaders.
14. Recognize and purpose your people to their strengths.
15. Praise your people in public.
16. Discipline in private with the intent to promote the success and growth of your people.
17. Be humble.
18. Take pride and care in your personal appearance.
19. Do not tolerate gossip.
20. Be adaptive to change.
21. Resolve conflicts fairly, consistently, and privately.
22. Get good at building relationships.
23. Forget your ego.
24. Don’t take yourself too seriously.
25. Admit when you’re wrong and do your best to correct it.
26. Be available to your people, but set boundaries.
27. Be trustworthy.

Less than 180,000 people currently serve in the United States Marine Corps. They are truly the few and the proud. So, even if you aren’t able to become a Marine, if you can drill these guideposts for personal development in deep, you have everything it takes to lead like one.