You've just written an important paper, business communique, or other document that will be read by others and perhaps will be the basis for a classroom grade, a prospective business arrangement, or provide necessary information for a specific situation. Regardless of the end use of this document, it is important to you that it not contain any errors or embarrassing grammar and punctuation mistakes. You've run spellcheck, but you understand that spellcheck isn't foolproof. Your document needs to be proofread.
Ideally, you need a professional proofreader (or some other objective person) to read your document and correct whatever errors there might be in it. However, time and circumstance are not always conducive to using a proofreader. When this happens, you have to proofread it yourself.
Self-proofreading is fraught with pitfalls, the biggest of which is that you are "too close" to the text. That is, you know what you meant to write, even if that's not exactly what you did write. Your brain can easily fill in the gaps and skim over simple errors like an incorrect wrong verb tense or a missed word in a well-used phrase. The mechanism in your brain that does this is called your "short-term memory"---and it can be very strong. Before you self-proofread, you need to allow your short-term memory (STM) to "dump" (that is, to allow what is stored in your STM to be deleted).
After you have finished your document---WALK AWAY. You need a minimum of 30 minutes between having finished the document and proofreading it. It is best if you do something that is completely disassociated with that document: work on something else that has no connection to the text in your document, go for a walk, make a few phone calls, or clean the cobwebs out of the corners of the ceiling. Clear your head in any manner you wish, but be sure to do it.
When you are ready to proofread your own document, do not read it from start to finish. It is best if you can print it; this will allow you to read it in non-sequential order. Read the middle two pages first, go back and read the beginning, and then read the last pages. Reading your text out of order will make it easier for you to see what is really there instead of what you want to see.
As you read along, if you "stumble" on any particular sentence, then go back and read it aloud. Yes---say the words. Better yet, put your finger under each word as you say it. This technique will help you to "hear" the error (maybe a wrong verb tense or a word that is missing). When you find an error (spelling, missing word, wrong word, missing punctuation), mark it on the printed page. You don't have to know proofreading marks---just use whatever shorthand you'll understand.
After you have read your paper, out of order, make all the corrections that you have marked. Be careful! It is really easy to insert that comma in the wrong place (and I'm speaking from experience here!). Key in the correction, and then review it on screen. Continue through your entire document, making all the corrections needed.
At this point, you should use "Find" to locate your trouble words. Perhaps you always waffle about whether to use affect or effect. Maybe you know that you often use it's when you should use its. Enter your trouble word(s) into the Find field, and click on Find Next until you have gone through the entire document.
Now you need to rerun spellcheck. For a tip on how to reset spellcheck (so that spellcheck will actually re-check the entire document, not just the changes that you made), go to "How to Re-Set Spellchecker," at: (http://freecontent.janktheproofer.com/ResetSpellcheck.htm).
If time permits, walk away from this document again for 30 minutes. Since you've already cleaned out the cobwebs, maybe it's time to rearrange your sock drawer. Come back to the document and skim through it one more time. If your brain stumbles over anything, read it aloud, put your finger under each word, and check for wrong verb tense, missing word, wrong word, etc. If you change even one thing, then you need to re-set your spellcheck and run it one last time.
Here's a final word of caution about spellcheck: Spellcheck does not always suggest the right thing. That is, spellcheck might stop at its and suggest that it is a commonly mis-used word, do you want to change its to it's. Don't get "Change" happy. When spellcheck beeps, look at the correction it is suggesting and then re-read the sentence in its entirety. If, in fact, you want to make the change suggested, then do so. If not, then hit Ignore and continue on. Likewise, don't get "Ignore" happy---every time spellcheck hiccups, review the change being suggested, re-read the sentence in its entirety, and make a decision to make the change or to ignore it.
There are many other ways that your computer can help you to produce a document that is free of error. For other helpful articles, please go to my index of Writing and Grammar articles at: http://freecontent.janktheproofer.com/#Grammar_and_Writing:.
Through intelligent use of your computer's word processing software, spellcheck, and your brain, you can produce an [almost] error-free document.