You burn something.
Avoid any last-minute disasters by make sure your food is close to ready—if not entirely prepared—by the time guests arrive. But if you do end up burning your sauce or overcooking your asparagus, don’t panic. Either have extra of your original dish on hand (twice as many vegetables, for example, or ingredients for a second batch of sauce), or have a backup dish. Make an extra side so that the entire dinner doesn’t rest on the success of one dish. Or, instead of having so many backups, simply prepare foods that can be made in advance. I can't stress enough how much this will help you. Some excellent ideas for make-ahead party dishes are short ribs, a sausage and kale tart, and roasted potato salad.