Go into the project with the understanding that an author has a lot of latitude right up to a fixed date — say, the first proof date — but no text changes will take place after that unless you find an embarrassing typo. (If you use a crack copyeditor, that won't happen. If there are none in-house, hire a freelancer.)
One tip that Castro offers printers is to give publishers (who can pass on to authors and designers) a 'drop dead' date — the absolute final date for revisions — even while, at the printer's end, there are in fact a few more days built into the schedule to allow for possible changes. So if more do come, deadlines still get met, and the printer appears to be bending over backward to make everyone happy.
Printers are not "all-purpose"
As a production manager for a book publishing house, I have found that the color proof stage often is the first point at which people involved with the book really sit down, take a look at the pictures and evaluate them. Raoul Goff, president of San Francisco-based Palace Press International, is correct to note that "clients make changes to ... images in the final stages of creating film or at blueline stage."
Goff suggests that if clients have the means to generate laser prints of images while the project is still at the concept stage, then they should do so. That's the right time, he says, to decide that a picture's light/dark contrasts give it poor quality. Maybe you should have it retaken, or maybe there's another one you should use instead. Then you'll go into the project with the lead time you need to do a meticulous job.
Communication is crucial
Regardless of how you plan the review and correction of your materials, be sure that others talk with one another. Some printers say they often lose time because a freelance designer sends them material with missing components, such as fonts or EPS files. In spite of the missing items, the publisher often expects the original schedule to hold.