1) After you finish writing it, put your document away for a while. Hours, days, weeks or even months. You want to look at it with "fresh eyes." Instead of seeing what you meant to write, you want to see what you actually did write. 2) Use the spelling and grammar features in your word processor. They aren't perfect - ask anybody - but if you know the rules, you can decide which suggestions to accept and which to ignore. 3) Know your weaknesses. Keep a list of errors you tend to make often, and use your word processor's search feature to help you find them. 4) Print your manuscript and edit it on paper. Away from the computer. You'll see more. I mark the printout with a pen, then go back to the computer to tinker, then print and repeat as needed. Different fonts, too, for the change of perspective. 5) Use a straightedge. If you're reading on paper, it can be a ruler. If you're reading on the computer screen, situate the document so the line you...