Flour tortillas can be made from all purpose flour, but corn tortillas are made from a special corn mix called masa harina de maiz. It is not the same as corn meal or corn starch. Here in Texas we can find it in every grocery store. Masa means "dough" in Spanish but in Mexico it almost always refers to masa harina. The corn used is very hard  which has been dried and soaked in a lime water (very similar to hominy), and then ground to fine flour.
 
 

A Tortilla Press

The wood for the press can be any food safe 3/4" or 1" scrap lumber but should be unwarped. The bottom piece should be cut from a 12" x 12" piece of wood with a handle the same widtth of the pressure arm. The uprights holding the pressure arm probably should be 1" x 2" so that you can use at least two screws to hold it to the paddle shaped bottom board. Use the 1" x 2" boards on the top and bottom plates for extra strength and to prevent warping. Locate the bolt at point where the arm can come down not quite horizontally over the top of the press. Use screws and glue to assemlble the parts together. You don't want the screws to come through the wood. Use longer screws to attach the hinges.

The above press is not the only way to make one. In Mexico you see metal parts, the pressure arm may be shaped and taped, and other variations. Most are very simple, efficient tools. Most look very rough.

2 cups Masa Harina
1 1/2 cups warm water

Mix together until dough can be shaped. Divide dough into 12 pieces and form each into a ball. Each ball can be shaped by patting it from hand to hand or using a press.

To use the press, place sheet of wax paper on the bottom. Position the dough ball on the wax paper. Place it slightly closer to the hinge. Put another sheet of paper of top of the dough. Now lower the top half and using the pressure arm press down firmly until the tortilla is about 6 inches in size. Stack the tortillas until ready to cook.

To cook, peel off one of the sheets of waxed paper and place the tortilla on a hot ungreased griddle. When the tortilla is warm peel off the top wax paper. Turn over and continue baking and turning until the tortilla had brown spots and looks dry. Don't cook until it is hard. The tortilla should be soft. Serve at once or cool and store in zip bags. They may be frozen. Tortillas may be reheated or fried to make taco shells or cut into wedges and fried to make tostados.

Coming: Flour tortillas, and some simple recipes to use with corn tortillas.