As an editor, I think the most important thing is to take the time to read each and every bit of text that needs to be scanned for errors and inconsistencies, and verify possible errors by consulting the appropriate style guide. Assuming things are spelled correctly and reported accurately shows laziness and leads to many of the errors that make it to print. I'm realistic enough to think that some mistakes are unavoidable, but I feel it is my responsibility to always try as hard as possible to avoid letting even the smallest of errors make it to print.