A warm, soft tortilla is a non-negotiable ingredient in great tacos. So here are a few different ways to heat them: You can wrap the tortillas in a damp paper towel and microwave them for a minute or so. Or, you can wrap a stack of them in aluminum foil and heat them in a 350-degree oven for about 15 minutes. Another way to heat a lot of them at one time is to "shingle" them on a baking sheet and heat them in a 400-degree oven for about seven to ten minutes. If you use this method, watch them carefully to make sure they don't dry out. If you prefer, you can also heat them individually in a skillet over medium heat for about 30 seconds per side. And, if you are lucky enough to have a gas stove, you can hold each tortilla over the flame to heat them.