Proofread backwards. Begin at the end and work back through the paper paragraph by paragraph or even line by line. This will force you to look at the surface elements rather than the meaning of the paper.
Place a ruler under each line as you read it. This will give your eyes a manageable amount of text to read.
Know your own typical mistakes. Before you proofread, look over papers you have written in the past. Make a list of the errors you make repeatedly.
Proofread for one type of error at a time. If commas are your most frequent problem, go through the paper checking just that one problem. Then proofread again for the next most frequent problem.
Try to make a break between writing and proofreading. Set the paper aside for the night — or even for twenty minutes.
Proofread at the time of day when you are most alert to spotting errors.
Proofread once aloud. This will slow you down and you will hear the difference between what you meant to write and what you actually wrote.
Try to give yourself a break between the time you complete your final version of the paper and the time you sit down to edit. Approaching your writing with a clear head and having at least an hour to work on editing will ensure that you can do a thorough, thoughtful job. The results will definitely be worthwhile.
Ask someone else to read over your paper and help you find sentences that aren’t clear, places where you’re being wordy, and any errors.
Try reading backwards, a sentence at a time. This will help you focus on the sentences, rather than getting caught up in the content of your paper.
Know your own patterns. Your instructor can probably help you identify the errors you’ve made most often in your previous papers, and then you can focus your attention on finding and fixing them.
Read through your paper several times, once looking just at spelling, another time looking just at punctuation, and so on. Again, this can help you focus so you’ll do a better job.
Use the spell-checker on your computer, but use it carefully, and also do your own spell-checking. Computer spell-checkers often make errors – they might suggest a word that isn’t what you want at all, and they don’t know the difference between there, their, and they’re, for example.
Get help. If you’re not sure if you need that comma or whether to use “affect” or “effect,” look it up in a writing handbook, or ask your instructor for help.
Remember that editing isn’t just about errors. You want to polish your sentences at this point, making them smooth, interesting, and clear. Watch for very long sentences, since they may be less clear than shorter, more direct sentences. Pay attention to the rhythm of your writing; try to use sentences of varying lengths and patterns. Look for unnecessary phrases, repetition, and awkward spots.