If you don't have someone who is willing to read the drafts of your new book, poetry, or essay, my best advice is you find someone who is willing to take the time to help you with this painstaking task, even if that means paying them to help you edit. Chances are you know at least one person who would be more than happy to oblige you with honest advice on how your manuscript measures up. Chances are also high that you will get some helpful feedback, that might not always be to your liking. When I was writing my first book, I had people giving me a lot of advice, mostly constructive, and always appreciated, but usually not taken into account. Looking back, I wish I had listened to the people who told me to add this or get rid of that part of my book. Whether you are writing a paper, article, or book, remember that you are not going to be the only one reading it when it is finished. Make sure that other people find your work to be great.
Many times, when someone puts a lot of time and energy into something that they love, it seems almost infallible. No changes should be made, because in their minds, it is already perfect. Some people will even get highly offended it they are corrected. Authors are no exception to this kind of blind arrogance, especially if they are already published and or successful. This might be one of the reasons that so many sequels or spinoffs created by the same artists are often lesser in quality then the original stories. Directors and authors who once might have taken critical advice now think that because they already have been successful no need of help. Likewise, those who might have good ideas quite possibly hold back their opinions because they assure themselves that the artists know better than them. After all, they are a successful published author, or filmmaker. Again, this applies to everyone not just authors. No one person is ever going to create great art, get consistent high grades, or rise in the ranks of the entertainment industry unless they take constructive criticism.