Extra tacos can be made in advance, wrapped in aluminum foil and stored in the refrigerator or freezer until you are ready to use them. Allow frozen tacos to thaw completely before heating. Store the tacos with meat and cheese. Do not add condiments such as lettuce, tomato and sour cream until they are heated through and ready to eat. When preparing the tacos for storage, avoid using overly juicy meat as this will make the tacos soggy. Also, if you quickly pan-fry the soft shells using a little cooking spray or oil, they will be more resistant to excess moisture. Wrap tacos individually for even heating.
Preheat the oven to 400 degrees F. The high temperature will heat the leftover tacos quickly not allowing them to steam for too long.
Place the wrapped tacos evenly spaced on the middle rack of the oven on a baking sheet. This will allow for proper airflow around the food.
Bake the tacos for 10 minutes. This should be long enough to heat the taco through and it could be eaten at this point.
Remove tacos from the oven and open the foil pouches. Then return them to the oven for an additional three to five minutes. This step will allow the taco shell to dry out a little if it has absorbed excess moisture.
Use an oven mitt when removing the tacos from the oven, and let them cool slightly before eating - if it's too hot to touch, it's too hot to eat. Top the tacos with additional condiments such as jalapenos, sour cream, lettuce, tomato and onion.
Do not use this method with hard taco shells. They will become soft and mushy as the taco heats in the oven.
Never place aluminum foil in the microwave.