In a large mixing bowl, mix together the masa harina, salt, oil and 1 cup water. Once combined, the dough should be a consistency similar to play-doh. It should not be sticky or crumbly.
If the dough is too crumbly, add 1 Tbsp of water until the the right consistency is formed. If the dough is too sticky do the same with masa harina.
Divide the dough into about 15-20 golf ball size portions.
To form the tortillas, use a gallon size Ziploc bag with the zipper removed and the sides cut open (or any thick plastic will work) and place the dough ball in between the plastic. To create the perfect round shell, press the dough balls with either a tortilla press or a casserole dish. Use consistent pressure to create an even thickness, about 2 mm thick.
Cook the tortillas on a griddle set to medium high heat or fry them in a fry pan with a little oil. Serve right away. Enjoy!