For me...It's all about continuous improvement and a commitment to always be learning.
One thing that killed my ability to grow was 'getting comfortable' and thinking I had enough knowledge to do the work.
But if I take it easy, my competition is getting better. So my 'one thing' would be to commit myself to be always improving my knowledge and skills.
Things are always changing. There will always be something new to learn
that is the truth. You can never rest because you competition isn't. Must always keep improving and getting better.