Use day-old bread if possible to prevent sogginess. For extra crispiness, lightly toast the bread before assembling. Cook sandwiches in batches to maintain heat and crispiness. You can customize the egg batter seasoning with nutmeg or smoked paprika. Substitute whole milk with half-and-half or cream for a richer batter. Variations include different cheese and meat options, adding sweet touches like honey or maple syrup, and vegetarian or gluten-free versions.