These aren't hard-and-fast rules or formulas but they are tried-and-true guidelines that hold true most of the time.
Getting quotes on a printing job
If a job is more than 10 percent of the annual printing budget, get six quotes. For smaller jobs, get three.
Proofing
If your eyes can see it, you need to worry about it. That's the rule for any faint mark or strange speck on artwork headed for the printer. Otherwise, if you want something to show up, it won't. And if you don't want something to show up, it will (a Murphy's Law type of rule).
Laser Proofs
Always print a laser proof of your file on your desktop printer. If your printer chokes on a file, chances are the imagesetter will be unable to print it either.
Indexing
An average index has three to five entries for each page of text. A light index has one to two entries. A scholarly or technical index has ten entries per page.
Proofreading
Two rounds of proofreading catch 98 percent of the errors in a publication.