Here are some tips to help you proofread effectively and thoroughly.
Use your computer spell-check and grammar-check features, but remember they are no substitute for your careful reading.
Proofread hard copies of what you’ve written. Errors are less obvious when you’re viewing them on a computer screen.
Put the document aside and review it the next day. What sounded great at 2 a.m. may not sound so wonderful at 2 p.m.
Read your message right-to-left or bottom-to-top. Your overly helpful brain wants to make sense of the writing and sometimes will read things that aren’t there. This strategy short-circuits the process and forces you to slow down to examine each word individually.
Ask a knowledgeable colleague to review what you’ve written. An objective reader often finds errors that escape the writer.
Consult a style manual (such as The Chicago Manual of Style) and a dictionary for proper writing style, word usage, and spelling.
Try temporarily changing the document to a different font. Errors sometimes jump out at you when the font is not what you usually use.
Concentrate on proofreading. It can be tedious work, so keeping distractions at bay is critical.
Read the document aloud. Your ear can catch things your eye may have missed. And you can evaluate the tone of the message as well as its content.
Go through the document several times. With each pass, focus on something different (spacing and white space; spelling; overall flow; consistency in styles for headings, fonts, underlining; sentence structure; punctuation; word choice).