A lot of really good answers in this thread. I had a great mentor years ago and she really taught me the importance of working cleanly and professionally. Proper code formatting, checking your comments for spelling mistakes, indentation, auto formatting on save, linting, writing solid documentation, rebasing and tidying up your commits to create clear steps that a reviewer can step through. All of the things that often get overlooked but are very important in how you come across as a professional developer.