Proof the content of your brochures before you print anything with the gold metallic ink. Print samples of the brochures without the metallic ink to ensure that all of the other colors look the way they should and all of the text is correct.
Have an expert set your rollers. You might feel like whoever normally sets the rollers on the printing press should be able to do it fine, but the first time you print with gold ink, have someone else do it first to ensure your first run goes smoothly and you do not have a bad experience. Test the rollers to make sure nothing is bleeding or the pressure is not pushing the ink out from the design.
Mix a very small quantity of the gold ink so it is very thin and runs off the palette knife. You do not want it thick, or it can stick unevenly and you might have to do the run again.
Wash the rollers when the ink starts to dry and get thick on the rollers or starts to cause poor quality work, usually every two hours. Have the expert set the rollers again and start a fresh batch of gold printing from the run.