There are a few schools of thought when it comes to baking meatloaf. Some say that covering the loaf pan with foil helps to keep the meatloaf moist as it bakes, while others say that baking it uncovered allows the heat to circulate more evenly, resulting in a more evenly cooked meatloaf. Ultimately, the decision of whether or not to cover your meatloaf while it bakes comes down to personal preference.
If you choose to bake your meatloaf covered, be sure to allow the meatloaf to cook for about two-thirds of the total cooking time before removing the foil. This will give the meatloaf a chance to brown on top and prevent the foil from sticking to the meatloaf as it bakes.
If you choose to bake your meatloaf uncovered, there is no need to preheat the oven. Simply place the meatloaf in the oven and bake according to the recipe instructions.