What You Need

Ingredients
2 cups masa harina
1/2 teaspoon kosher salt
1 1/2 cups hot water (hot tap water is fine)
Equipment
Mixing bowl
Measuring cups and spoons
Spatula
Tortilla press
1-quart zip-top bag or layers of thick plastic
Cast-iron griddle or skillet (see Recipe Note)
Clean kitchen towels

Instructions

1. Prepare the tortilla press: Cut the zip-top bag open along the sides. Open the tortilla press and lay the opened bag on top. (The plastic can be reused indefinitely; just wipe it clean of any dough after each use.)
2. Mix the tortilla dough: Mix the masa harina and the salt together in a mixing bowl. Pour in the water and stir to combine.
3. Knead the dough: Using your hands, knead the dough for a minute or two in the bowl. The dough is ready when it's smooth, but no longer sticky, and easy forms a ball in your hand. The dough should feel a bit "springy," like Play-Doh.
4. Adjust too-dry or too-wet dough as needed: If the dough absorbs all the water but is still dry and crumbly, add water a tablespoon at a time. If the dough feels sticky, paste-like, or gummy, add more masa a tablespoon at a time.
5. Rest the dough (optional): If you have the time, cover the bowl with a towel and rest the dough for 15 to 30 minutes. This gives the masa time to fully absorb the water and improves the taste and texture of the tortillas. You can skip the rest period if you're in a rush.
6. Roll the dough into balls: Pinch off a few tablespoons of dough and roll it between your hands to form a ball roughly the size of a ping-pong ball. This will make roughly a 6-inch tortilla, and you can adjust the amount of dough you use to make larger or smaller tortillas.
7. Press the dough with the tortilla press: Place the ball of dough on the plastic-covered tortilla press in the middle of the press. Fold the other side of the plastic bag over the top of the dough. Bring the top of the press down over the dough, then press with the handle to flatten the dough to about 1/8-inch thick. If the tortilla doesn't look quite even after pressing or you'd like it a little thinner, rotate the tortilla in the plastic and re-press.
8. Peel the tortilla off the plastic: Peel away the top of the plastic, flip the tortilla over onto your palm, and peel off the back of the plastic.
9. Continue pressing tortillas: You can either cook the tortillas as you press them, or you can press all the tortillas and then cook them. Keep both the dough and the stack of pressed tortillas covered with clean towels. If you choose to press all the tortillas and then cook them, be careful when peeling each tortilla off the stack — they can stick to each other or break around the edges, especially the ones on the bottom.
10. Heat the griddle: Warm a large, flat cast iron griddle or skillet over medium-high heat. When ready, a few drops of water flicked onto the surface should sizzle immediately and you should be able to hold your hand an inch above the surface for just a second or two.
11. Cook the tortillas for 1 to 2 minutes on each side: Gently position as many tortillas in the pan as will fit in a single layer without overlapping. Cook for 1 to 2 minutes, until the edges are starting to curl up and the bottoms look dry and pebbly. Flip and cook another 1 to 2 minutes on the other side. When done, both sides should be dry to the touch and beginning to show some brown, toasted spots.
12. Wrap the tortillas in a towel: As you take cooked tortillas off the griddle, stack them up and wrap them in a clean kitchen towel. The tortillas will be a bit dry and brittle just off the griddle, but will continue to steam and soften inside the towel as you finish cooking the rest of the batch.
13. Serve immediately, or cool and refrigerate for up to 3 days: Fresh corn tortillas are best when they're just off the griddle and still warm, but leftover tortillas are still very good! Let any leftovers cool completely, still wrapped in the towel, then put them in an airtight container or zip-top bag and refrigerate for up to 3 days.
14. Reheating tortillas: Dampen a kitchen towel or paper towel slightly and wrap the tortillas loosely. Microwave in 30-second bursts until the tortillas are warm and pliable. Eat immediately.

Recipe Notes

• Making tortillas without a press: You can also use a rolling pin to flatten the tortillas, though it's trickier to make perfectly round tortillas. Start in the middle and roll out to the edges. You can also try flattening the tortillas beneath a heavy skillet.
• Cooking tortillas in stainless steel or nonstick skillets: If you cook the tortillas in stainless steel, brush it with a thin layer of oil between batches to help keep the tortillas from sticking. If you cook in a nonstick skillet, lower the heat to medium and cook the tortillas a little longer.
• Make tortilla chips! Any leftover tortillas that become too stale or dry to eat as tacos can be fried or baked into tortilla chips. Here's how:

source : http://www.thekitchn.com/how-to-make-corn-tortillas-from-scratch-cooking-lessons-from-the-kitchn-85904