You are being judged all the time. All the time. So you want to be sure that you are showing yourself at your best. Of course, you will make mistakes, perhaps for "Freudian" reasons, perhaps for other reasons, perhaps because you are overworked or lazy. But in so far as you can do so, always put forth your best.
If you are going to submit work to your boss or teacher or a journal, be sure to read over the final version to catch any mistakes. If you are setting up a website, check that all the links work, and that they link to the right files or media. If you are giving a presentation, you want to practice and be sure what you say is both clear and within the time limit.
I have made just about every mistake one can imagine. That's why I write about these issues. I am not saying that I or anyone is a paragon here. Rather, you just want to keep in mind what you must do if you want to do something and go someplace.
Everyone knows just about everything I write about in this blog or in my other blog. I hope it is worth stating even what I am saying is a commonplace or moral cliche.