Tartine Bakery's Country Bread
Robertson describes a starter -- a mixture of flour, water, wild yeasts, and bacteria -- as a baker's fingerprint. Making one is simple, but it does require a commitment: Count on feeding and caring for the mixture for three weeks before you start baking. For something closer to immediate gratification, begin using the starter after five to seven days, or order a fresh starter at kingarthurflour.com. (Keep in mind, the flavor won't be as complex.)
Another secret to baking like a pro: Weigh all the ingredients-even the water-using a kitchen scale that includes metric measurements.