Practice humility like you practice any other skill. Being humble keeps you from slipping. As soon as you think you do not need to do the things that got you where you are is when you start loosing and making mistakes. Being humble allows you to take criticism because you know who you are and you can make fun of yourself.
Be humble enough to know that there is still more to learn. You are not at the end. You are still growing every single day. The world is your teacher and you are its student. Always be open and receptive to listen to what the world is trying to tell you.
If you are real about what you want and are humble enough you will find things in unexpected places. You are not above anything.
Be humble because there is always someone better than you. Learn from the competition, find mentors, read books, and practice everyday to get better.
Put in the time to get better every single day.