(1) Use tabs, not the space bar, to align type.
(2) Word-processing programs may not print on an image setter with the same line and page breaks as on your office printer. The best solution is to save the document as a .pdf file as well as providing the original document.
(3) Delete extra blank pages and any clutter, such as unused type, boxes, and art, that remains on the pasteboard.
(4) Provide a proof usually a pdf of the most current version of your document.
(5) Place copies of your document, fonts, art, and photos in the same folder so that files link properly.
I need to stick this on my board every time I talk to a new client. Some are still sending me .pub files *grin*