Here's the basic method I use: Cover, then let rise overnight. Transfer to the fridge, let ferment for three days, then turn dough out on to a well-floured surface. Shape dough, sprinkle with flour, and cover with a floured cloth. Let it rise for at least two hours and up to 4 at room temperature.
This is achieved by using a water pan with a kitchen towel in it for slow steam release, preheating the oven slightly higher than the baking temperature, and spraying a bit of water in the walls of the oven after the bread is in. Proper scoring improves the oven spring and, hence, the openness of the bread's crumb.