To keep dips cold, slice off the top from a round loaf of bread and remove the inside of the bread, leaving a 3/4-inch shell. Put the round in a freezer bag and freeze. The day of the party, pour the dip into the frozen bread round. It will keep the dip cold for 4 to 6 hours. To keep items like meatballs or mulled cider warm, put your slow cooker to work, on the "warm" setting.