Keep your carbon food-print (sorry, we had to) low by serving a seasonally-inspired menu, shopping at local grocers and delis rather than big-box stores if your budget allows it, and serving dishes that accommodate people's dietary preferences to make sure they get eaten. Instead of providing plastic water bottles, prep some jugs of chilled water, perhaps infused with a little fruit.
Make recycling bins visible if you're serving canned drinks, and have a compost bin ready for any food you can't eat or give away. Additionally, serving and keeping food at the right temperatures (the CDC has tips on how to do so) ensures that you can safely keep it as leftovers, rather than throwing it away.
