Whisk together masa flour with salt in a large bowl. Slowly pour in the warm water and mix with your hands until it forms a dough. If the mixture seems dry, add a little more warm water. You'll know it's perfect when it all comes together off the sides of the bowl.
To form the balls, pinch off a small amount of the dough, about 2 tablespoons worth, and roll into a ball.
Prepare the tortilla press by lining it with wax paper or plastic wrap. Place the tortilla ball in the center then gently press to form tortilla.
Heat over a warm skillet, about 90 seconds per side, flipping once. There's no need to oil the skillet but you may if you wish. Keep tortillas warm inside a towel until you're finished making all the tortillas. Serve warm.