Ideally, says Miller, of HomeProHub, on a big job your pro should spell out every step, expense, and setback on a dedicated website that's accessible to all, using snapshots and software, such as Co-Construct, designed to manage projects. But even if your pro prefers pencil and paper over keyboard, documentation is essential. Mysterious expenses often lead to distrust, says Miller, "and sharing information with homeowners really eliminates this problem." Lynn McBride, who has survived—and blogged about—home renovations in spots as far-flung as Charleston, South Carolina, and Balleure, France, advises using the specs in the bid as a checklist. "I used to track every detail in a three-ring notebook," she says. "Today, I'd stick it on my iPad.