The really good and professional writers are not the ones who only have a few mistakes in their writing. They typically revise multiple times, and not just small revisions, they make big changes. You should revise globally and locally. Revising globally means to change things that will affect other parts of the writing, not just the one you’re fixing; revising locally, means it will only really affect the one or two sentences you are working on. Multiple drafts can help your short term memory by rereading and recreating the writing you already have. It can also help you develop your ideas better, and the audience you are writing to. You should also have a plan of what you are about to be writing. When you begin writing something, it shouldn’t be the first time you are putting the ideas down on paper. Also, you need to make sure you have the correct amounts of time to get every part and process done that you need to. For some writers, revising their writing takes even longer than the actual writing itself! As you are writing, think about the audience you are writing to, instead of you yourself. Your writing should accommodate to them and the things they appeal to. Lastly, don’t be afraid to exchange your writing with others for feedback, it helps to get more opinions than just your own.