In a large mixing bowl, combine masa harina and salt. Slowly pour in warm water and mix with your hands until incorporated. Knead mixture until you have one large ball of dough. Pull a small bit of the dough off and roll into a ball to test the consistency. Squash the ball gently between the palms of your hands until about a quarter inch thick. The dough should squish easily in your hands without being too sticky and form a flat disc with rounded edges. If the disc has rough edges, it is too dry, and you need to add more water. If the dough sticks easily to your hands, it is too wet and you need more masa. Pull and equal size portion of dough from the larger piece and roll into a ball just larger than a golf ball. Place on sheet tray lined with parchment paper and repeat for all the dough. Keep the dough ball covered with a damp towel as you work to keep the dough from drying out. Heat comal over medium high heat. Put 2 6â€ round pieces of plastic (such as from a plastic shopping bag) and place one on the bottom of a tortilla press. Place a masa ball on the plastic and cover with the second plastic disc. Close cover and apply enough pressure to flatten the dough into a 5â€ tortilla. Lift lid of press, gently peel away the top layer of plastic, flip in your hand and peel away the other piece of plastic. Place tortilla on heated pan and cook 30 seconds, until bottom starts to brown and bubble. Turn tortilla over and cook 30 more seconds. Remove and set aside. Cover with a clean towel to keep warm. Repeat with remaining dough, stacking the tortillas on top of each other after cooking.