have the nutriten facts about the food you're serving, not only available, but also have a sign up that says the information is available upon request. People who have specific dietary needs, or who are trying to watch what they eat will be more likely to visit your establishment again if they both know that they can get this information, and feel that asking for it is not an inconvience to the people that work there.
If you will have a drive through, instruct your employees that they should not ignore a customer who is in the restaurant just because their is a line outside. First come first serve is fair. I once felt like demanding my money back and telling the person behind the counter to shove their food where the sun don't shine, because from the time I placed my order and payed, they put together about 6 orders for the drive through before they bothered to get me mine. (If I hadn't been picking up food for someone else also I would have done just that, and then contacted corporate).
If customers are going to fill their own cups with the pop, have lables for the lid sizes. Some people aren't very good at 'eyeing' which size lid goes with which size cup, having a lable that tells them which is for small, regular and large will save on the lids getting tossed because someone guessed wrong (at least I'm hoping people throw them away and don't put them back -_-; )