Purchase surety bonds. Surety bonds essentially act as a kind of agreement between the contractor and the person hiring them that the job will be performed to standard. You can obtain these through your current insurer as a separate form of financial protection. As a contractor, many states require you to be bonded before you can begin working legally.
Here is where this affects you as a consumer. You select a painter with a contract that says 2 coats, $500 down. You give the company the deposit and pick your colors a couple of days before the project starts. The painter goes to the store with your colors and figures out they are deep base. He (or she) not only needs to charge you more for the paint, but he also needs to charge you for a dark gray primer coat. Ninety nine percent of the time that primer coat is going to be really, really expensive since you already gave a deposit.