Proof yeast in warm water and sugar for 5 minutes in a large mixing bowl.
Stir in flour and salt. Mix well.
Let rise 1 hour at room temperature covered with plastic wrap. Plastic wrap is needed to seal in the heat and moisture during this rise.
Knead and shape on floured surface into desired loaves. I prefer boules (rounds) or baguettes (long). Only knead it enough for it to come together into a ball, not too much. Place on parchment-lined baking sheet or in floured bannetons/bowls on a parchment-lined baking sheet.
Cover with a hot or at least warm damp cloth. It needs to be warm to start, even though you are putting it in the fridge. Refrigerate overnight or at least 8 hours. (You have some wiggle room here since it is refrigerated.)
Heat oven to 450 degrees Fahrenheit for at least 45 minutes with an empty cast iron skillet on the bottom rack.
Set loaves out at room temperature for fifteen minutes before baking (last 15 minutes of oven heating time). Remove any loaves from bannetons or bowls by flipping the bowl over onto the baking sheet. (Do NOT put bannetons in the oven or bake these loaves in bowls.) The top of the loaf is what touched the inside of the banneton/bowl. Lightly flour the tops and slit as desired just before putting the loaves in the oven.
WEAR OVEN MITTS AND BE CAREFUL!!! After placing the pan(s) in oven, CAREFULLY and WELL PROTECTED FROM THE STEAM pour 1 cup of water into the skillet.
Bake for 25 minutes or until the crust is golden brown and the loaves sound hollow when tapped.
Cool on wire racks.