If you are about to close (as in 5 mins), tell the customer when they walk in not midway thru processing the order. After a long day, I really just wanted to sit down and enjoy my sandwich without the feeling of being hurried out the door. I discovered they were closing when I was told the condiments had all been put which I was told near the end of my subway experience and the sandwich person would only bring out what I specifically asked for (been awhile since I was in one so I missed the spicy mustard... this part bugged me the most).... Then of course knowing they were closed I really couldn't just sit and enjoy the sandwich so I left. What I would suggest is put a visible sign on the glass door you are closing in say 15 minutes, or just state that you are closed.