The Roadrunner's Guide to English: Proofreading
At the proofreading stage, you are sure that you have all the sentences you want and that they’re in the right place. At this point, you can start cleaning up any typos or grammatical errors. If you’re able to work at home or some other private place, try reading your work out loud; this helps many writers find mistakes. If you’re working on a computer, print your essay out or change the font so that it looks different; sometimes that helps in spotting errors, too. Finally, try reading the essay “backward.” Read the last sentence first, then read the sentence before that, etc. This can help you really focus on what the sentences actually say. When you read over something you’ve written in order, sometimes you unconsciously “correct” it, seeing what you meant to write instead of what is actually on the paper.