Beat eggs, milk, vanilla, and salt very well in a medium mixing bowl or a large measuring cup. Beat until appearance is uniform with no visible egg pieces showing.
Heat a flat skillet or griddle over medium heat. Place butter on pan for more flavor, to encourage a golden brown color, and to prevent French toast from sticking to the pan.
Dip a piece of bread into the egg mixture and let it soak up egg and milk mixture for 10-15 seconds on each side. Let excess egg mixture drip off before placing French toast on heated griddle.