On texts of some length, proofreading/editing is often the final step in the writing process prior to publishing your text. Proofreading usually takes place nearer the end of the revision process than at the beginning. Why? Because it doesn't make sense put in the effort to proofread looking at every sentence and word level issue until your draft is fairly solid. In other words, why proofread and edit sentences and words which might still be cut? Why proofread haphazardly when you can proofread systematically after you've finished most revisions and save effort and time?
Here are my own notes on proofreading. Those just below are the main ones to remember:
It's nearly impossible to effectively proofread your own work. You know what you mean to say. When you read your own work, you often read over mistakes. My best piece of advice is to get others to proofread your work. Try to get at least three people to look at your work prior to turning it in. If necessary, hire someone or create a writer's group to help you with proofreading.
EVERYONE makes mistakes. Don't kick yourself for your mistakes, learn to recognize them and how to fix them. Even then, you'll still make mistakes.
I once worked for an academic journal. Four sets of eyes proofed each article--the professor who wrote it, myself, the departmental secretary, and the editor. Still, EVERY time we got the journal back from the printers, I opened it to a random page and found at least one mistake. EVERYONE, even professionals, make mistakes.
When you proofread, you're trying to do something called breaking set. This means you want to change the way you usually read, so you don't read over mistakes. Most of the proofreading tricks I list below have to do with changing how you read, so you can see what you've written.
1. Give yourself time to proofread. It's easy to find yourself adding the last sentence to a text at the last possible minute. As we finish drafting, the last thing we want to do is acknowledge there's yet more work to do. We want to be done. Resist the temptation. Give yourself time to proofread. Your final product will be better for the time. To give yourself time, set your deadline for finishing your draft in time to revise the draft for content and structure and to still have time to proofread.
2) Read backwards from the last sentence to the first. When proofreading for spelling, read backwards one word at a time. Learn to isolate each word, even those which have been passed by the spellcheck. It doesn't catch every misspelling. When proofreading for sentence issues, read backwards one sentence at a time.
3) Read slowly and out loud. You'll be surprised how reading something out loud, as opposed to silently, will let you hear errors you'd otherwise overlook.
4) Read to someone else. Reading your paper to someone else forces you to take an audience into account. Not only can the person you're reading to ask questions about content, they can mark places in a copy of your paper where they're confused or they hear an error as you read. When you hear a mistake or a piece of awkward phrasing, you can mark it and come back later to fix it.
5) Print out your text. If you usually read your papers on the screen, make a hard copy. As you find errors, mark them, and later revise your electronic copy. When we're drafting and hit the creative zone, we often work quickly and have a hard mental focus on meaning. These habits of reading quickly and thinking in terms of meaning and adding or cutting content can track over into efforts to proofread on the screen. Remember, when you're proofreading, you're not so much worried about content or organization (hopefully, each of these elements was polished earlier in the writing process), when proofreading you're looking at mechanics, usage, spelling, and grammar and only at mechanics, usage, spelling, and grammar.
6) Get someone else to read your work to you. Print out two hard copies. Get a friend to read your work to you. Both of you mark places which don't make sense or appear to be problematic. Use both copies as an index when fixing your text. Go back and look at each place which was marked and try to figure out what caused the area to get marked.
7) Have the computer read the text two you. Make a hard copy and set up the computer to read the text out loud. It will read what's there. Every time you hear an error, mark your hard copy. Use your marked copy as an index to what needs to be fixed.
8) Give yourself time. Breaking set isn't just about reading backwards or reading out loud. You get close to a text when you draft it and work on content and structural revision. If you try to proofread after working this closely with the text, you'll find yourself seeing what you meant to say rather than what you're actually saying. Horace, a Roman rhetorician, recommended putting what you write away for nine years, that is, until it reads as if someone else wrote it. We don't have such luxury, but giving yourself a day or two to let the text set, even just doing something else between finishing your content revisions and proofreading, gives distance enough so you're can bring fresh eyes back to your text. So, finish your draft and reward yourself with a night's sleep, a night out, or a workout prior to proofreading.
9) Give yourself time to proofread. Slow down. You're not in a race to get through, you're trying to look closely at multiple things, and the process takes time. Slow down. Read slowly. Take the time it takes to truly see and truly edit every sentence and word.
10) Physically touch every word. Talk about breaking set! Read backwards. Read out loud, and touch every word to make sure you're seeing and proofreading each and every word and sentence.
11) Use the grammar and spell checker. The state of the art in grammar and spell checkers isn't quite there yet, but they can help you see some errors. Just don't their word as law. Use them for the things at which they're effective. They can isolate "to be" verb constructions and give you an index to possible passive voice constructions. They can show you long sentences. They can usually recognize subject verb disagreements. They can sometimes help with punctuation. The real trick with using grammar and spell checkers is to learn their weaknesses and to learn how to customize them to the style of writing you want to reproduce.
12) Boo-boo or demon words. You know these words. They're the ones which sneak through the spell checker. Usually they're jargon or proper names you misspell or forget to capitalize. You can customize autocorrect to make corrections for your most typical boo-boo words.
13) Use a ruler or a piece of paper to isolate the sentences you're proofreading. This practice forces you to look at the sentence you're proofing, not the next sentence, not the previous sentence, the sentence you're supposed to be looking at.
14) Learn your problem areas. Everyone is prone to making different mistakes. If you or someone else sees a pattern in your mistakes, put it on a personal "list of things I have to look at when proofreading." (This is why it's a good idea to read the papers you get back from teachers and proofreaders. Often your professor will mark errors. Use their work to help develop your list of "things at which I have to look.") By learning to recognize the problems you're prone to introducing into the text and how these errors can be fixed, you'll soon find yourself making fewer errors. Every once in a while, take your copy of "things at which I have to look" and find your worse error. Spend some time researching how to recognize and fix your worse error. Eventually, you'll find your list of common errors getting shorter and your sentence level writing improving in proportion.