Prepare tea sandwiches up to one day in advance of an event, and store them in an airtight container in the refrigerator. Cover the sandwiches with a sheet of wax paper and a damp paper towel to prevent the bread from becoming dry. Uncover sandwiches right before serving. Some sandwiches can be frozen if made ahead of time, however sandwiches with egg, mayonnaise or salad dressing based fillings do not freeze well.
When freezing tea sandwiches, roll them tightly and wrap in wax paper. Roll each sandwich into the waxed paper like a jelly roll. Tightly wrap each sandwich twice in plastic wrap and freeze for up to three weeks.
Sandwich fillings that freeze well include cream cheese with fruit or nuts, such as crushed pineapple, deviled ham with mustard or pickles, olives and cream cheese, and mashed shrimp with butter. Sandwiches filled with thin slices of ham, smoked salmon or roast beef along with cheese and pickles also freeze well. Sandwiches filled with a cheese spread freeze well if the cheese spread has a butter base and not a mayonnaise one.