Prepare a baking tray by lining it with paper towels. In a medium- to large skillet, melt 1/4 of the oil over medium heat. Using a thermometer set to 350 degrees Fahrenheit, add the tortilla and sauté for 12 to 15 seconds, or until the first side is golden and bubbly.
Flip and divide in half immediately using tongs. Fry for an additional 10 to 12 seconds per side, or until golden brown, then transfer the taco shell to the prepared baking sheet using utensils.
Sprinkle taco casings with kosher salt immediately. I've discovered that by slightly inverting them and allowing them to chill and drain on the paper towels, they retain their open shape for a longer period of time, thereby obviating the need for a taco holder. Proceed with the remaining tortillas in order to fry every shell.