Not a problem that had occurred to me:
Always have a loaner spoon available. In weightlessness, it is easy to lose things. It is not unusual in a group of six for someone’s spoon to have floated off. Having a clean loaner spoon allows for the evening to continue and the conversation to flow. It is rude to give your guest a loaner spoon caked in crud from the last time it was used. The lost spoon is usually found by morning, stuck to a ventilator inlet screen, and your guest will appreciate it being returned.
You can provide a special treat if you have access to one of the research refrigerators. In space, all your food is either hot or at room temperature. When you live in an isothermal environment, it can be a real treat to serve your guests a bag of cold water.