There's a lot of advice out there about the techniques and gear a professional photographer should be aware of and use, and while those are certainly good things to know, there's another aspect that often gets overlooked, even by seasoned photographers.
Coming to you from Daniel Norton, this great video talks about professionalism and reliability. My composition teacher always told me: "there are a lot of mediocre composers out there with careers, simply because they show up on time and deliver what they say they will." Of course, he wasn't advocating settling for mediocrity, but rather emphasizing how far having a reputation for being reliable and professional will carry you. It's easy to overemphasize other aspects of growing as a photographer at the expense of ensuring you're developing a strong professional reputation. This is why you hear a lot of successful professionals say that being a photographer is really about being a problem-solver, because at the end of the day, your paying client doesn't care that it's raining or that your flash just died; they want the results they paid you to create at the expected time, no excuses.
Lead image by rawpixel, used under Creative Commons.