a cardboard box, some paper cups, some glue, a box cutter / utility knife to cut cardboard to size, and an ink marker.
Find a box for the base of your tray. I am using a wine box since our local grocery store has them at the checkout lane for your purchased goods.
How tall are your cups? I am using 3 oz but you may want a 5oz tray also. I cut my tray just below the height of the cups so determine where that is on the box. My wine box already has a nice line defined in the printing.
Cut your tray to height following all known & sane safety guidelines … preferably on scrap cardboard or other cutting surface and not your favorite antique table.