The ingredients are simple - a bag of corn masa flour and some water. I used 2 cups of masa, and 1 1/4 cups of water. Depending on how many tortillas you want to make you would adjust the amounts accordingly.
Mix the masa and water together in a bowl. The mixture needs to be a dough like consistency. If it's too dry, add some water, about a tablespoon at a time.
Divide the dough into 16 pieces (or however many tortillas you will be making). Roll each piece into balls. Cover with a wet cloth to keep moist.
The dough can be rolled out into a circle using a rolling pin, but the tortilla press is much easier. The tortilla press needs to be lined with plastic wrap or a freezer bag can be cut into 2 circles and used instead (that's what I used so I could just wash and store it with the press). Place one piece of plastic on the bottom of the press. Place the dough in the middle of the bottom plastic and cover with the top plastic.
Flatten the dough in the tortilla press. I recommend that you don't just flatten it in one push. I pressed a little, opened and turned the dough a little, pressed again, and so on until I got the right thickness. All in one push made mine a little uneven.
Remove top plastic and turn tortilla over onto your hand. Gently peel off the bottom piece of plastic and lay the tortilla into a heated (med-high heat)m ungreased cast iron pan. Cook for about a minute on each side.