"I think it's very important to have a feedback loop, where you're constantly thinking about what you've done and how you could be doing it better. I think that's the single best piece of advice -- constantly think about how you could be doing things better and questioning yourself."
This is a part of Musk's work ethic and what makes him a good leader, even if the feedback is not what you want to hear. But in trusted teams and positive work cultures, negative and constructive feedback will stretch you to learn new things and consider other, better, options. Musk also once stated, "Don't tell me what you like, tell me what you don't like."
The feedback loop is unquestionably part of every leader's growing process. This is how managers win the hearts of their people -- by being open and sharing plans for the future, communicating important things to their people, and fostering a transparent culture of giving and receiving feedback on no less than a weekly basis.
But first, hire the smartest people you can find
Like Musk, the smartest leaders open to receiving feedback will focus on hiring even smarter people to provide them with consistent and truthful feedback.
Take Steve Jobs, for example. He may have had an enormous ego as the head of Apple, but he understood his place in the information age when he famously quipped, "It doesn't make sense to hire smart people and tell them what to do; we hire smart people so they can tell us what to do."
Whether you're aiming to improve on a particular product or service, management style, business process or something else, your best move is to intentionally not be the smartest person in the room; you hire people brighter than you, add humble pie to your diet, and solicit consistent feedback to improve yourself and the business.