Consider which material best suits your needs. Flimsy materials are usually cheaper and work great hung on a wall, but if the signage needs to be free standing, a studier, more expensive material might be more appropriate.
Call print shops and get specifics on the desired file type and settings for exporting. A wrong file type can be incompatible with their printers.
Examine the file for typos, misplaced shapes, and color issues. Double-check that the file has no errors, because the print shop will print exactly what you send them.
Export file in the vector design software, according to print shop specifications. This typically creates a PDF or EPS file. Send finished PDF or EPS files to the shop. Follow the shop's process for sending files, which may include email or uploading them remotely to their FTP server.
Examine printed signage when you pick it up at the shop. Look for any issues or damage caused by printing. These can include garbled lettering, damage to the corners, or faded coloring. Ask for a reprint, if anything looks unsatisfactory.