Design the poster using a document size proportionally smaller to its final size (e.g. if the final poster size is 30" x 40", lay it out on a document size of 15" x 20"). This will allow the printer to enlarge the poster without gagging on a large file.
When using fonts other than System fonts (Arial, Helvetica, Times etc) be sure to include the original font files otherwise you may end up with a default System font.
Make sure that your images and logos are not taken from the Internet. The reproductive resolution of Web images is generally too poor for high-quality, large-format printing. 300 dpi EPS, TIF and JPEG (with minimal compression) formats are generally fine for images and logos.
Supply original images whenever possible. Images embedded in presentation or word processor programs (PowerPoint, Word, etc.) may limit the ability to enlarge your figures.
When checking for approval, make certain to read your text thoroughly. It is not uncommon for design software to mistranslate symbols when importing from other file formats.
The title of a poster should state the conclusion of the investigation rather than the process of what was done.
The heading should include the authors' names and affiliations.
Lettering for titles should be readable from at least 6 feet away - use no less than 1-inch high type.
Words should be spelled out, avoiding mysterious abbreviations to decode.
The text, tables and graphics should look integrated. The same typeface should be used for all content.
Lines of text should contain about 10 to 12 words.
Lettering for text in the body of the poster should be readable from at least 4 feet away - use no less than 1⁄2 inch high type.
Tables are preferable to graphics for small data sets or when data presentation requires many localized comparisons.
Explanations should be used to enhance access to the richness of data and make graphics more attractive to the viewer.
Words and illustrations should go together - tables and graphics should be integrated within the text whenever possible, avoiding clumsy diverting segregation.
Little messages help explain data. Labels should be placed on the graphics itself so no legend is required.