What you see here is what you'll get on press. If you do find any mistakes or problems, mark them neatly and carefully with a red pen. No pencils, please - the marks are too easy to overlook. In most cases, we will issue you another proof with the corrections made for your review. Frankly, if time allows, we'd rather provide you with a new proof just to be on the safe side.
Mistakes are too easy to make.
Establish a proofreading system and make it an integral part of the project. First, make sure someone in your office is assigned to proofread. Too often, clients assume designers proof, designers assume writers proof, and so on. Your proofreader needs to be someone who is conscientious and detail-oriented. Recognize that proofreading is a skill - don't just pass off this very important task to the lowest person on your office totem pole.