Editing Editing Editing is eliminating the surface errors in your writing, so you might want to review the material on error you studied earlier. Seldom will you find any if you are no more systematic than that. I don't know what an error looks like. Errors, when they occur and need correcting, are very specific, but the word error is vague and useless.
Efficient readers learn to ignore most of what they see in writing.
They guess ahead, which is what they are supposed to do, especially with familiar material. But proofreading is carefully checking to see that all the things readers get to ignore are correct. The only reason readers get to ignore some things on the page is that they can be confident that the signals they actually see are correct. Proofread once for every kind of error that habitually troubles you. At first it is slower to do your proofreading this way, but given that you actually find errors instead of missing them, it's worth it.