Using a skillet to warm and soften up your tortillas is the old-school traditional way to do it. It is perfect for taco recipes, and you can soften it with or without oil.
Softening your tortillas in the oven might take a little bit more time, but it requires minimum effort from you. This should take about 20 min.
A tortilla warmer is a pouch or a container that will hold your tortilla soft and warm. There are so many kinds of tortilla warmers.
Corn tortillas not only break when they are cold but also when they are dry. If you have left a bag of store-bought tortillas open for a long time and they have lost their moisture, try to steam them
If you have already opened a bag of corn tortillas and have not used them at all, it is better to freeze them instead of keeping them in the kitchen cupboard. To defrost them, take them out of the refrigerator, leave them in the fridge for 24 hours.