Heat the pan / skillet to a medium to high temperature. No need for oil as tortillas are cooked dry
Put the flour in a big mixing bowl, add the salt and mix well.
Pour the hot water over the dry ingredients and mix using a fork to prevent burning your fingers. The dough should be wet without being too sticky. If it is the first time you make them, cover the bowl with a wet tea towel to retain moisture while you figure out the process. If the dough goes dry, wet your hands slightly when handling the dough as this will add extra moisture and the tortillas will be smooth and easier to handle. Dried dough makes tortillas brittle and cracked around the edges.
Take enough dough to form a small ball in your hands, about the size of a golf ball.
Open the tortilla press and line it with one of the plastic sheets. Place the dough ball in the middle of the lined press and cover the ball with the second plastic sheet. Close the press and push down firmly a couple of times to shape the tortilla; it should be thin, without being paper thin.
Peel the top plastic sheet from the tortilla. Then carefully peel the tortilla off from the bottom plastic sheet. Trust me, it should be easier than it sounds!
Place the toritlla in the pan / skillet and cook it for 10 seconds on that side. You will notice the tortilla skids in the pan; flip it with an egg lifter and cook it for 50 seconds on that side, then flip it again and watch it rise and fill with steam. Less than a minute should do it. This 3 side cooking must be observed if you want good quality tortillas.
If you are using your tortillas right away, place them them in the tea towel and cover them immediately to keep them warm. If you stack them, they'll keep the heat well. Remember that tortillas have a soft and hard side, always place the soft side, the one which rises with steam, facing up, this will prevent them from sticking.
If you are making them in advance, cool them well before stacking them. Wrap them in a clean, dry tea towel and put them in a plastic bag well sealed. They can go on the fridge now and should last up to a week, providing no condensation or too much air gets into them. To reheat them, just place them in a hot dry pan and heat them in both sides for a few seconds. Depending on the size of your tortillas and how big the pan, you can heat 2 or 3 at one time. They should go soft and fluffy again. You can also reheat them in a microwave wrapped in a tea towel for 1 to 2 minutes.