Be suspicious of any deal offered for "today only", accompanied by pressure tactics, a "special price" if you sign right away or with large cash deposits required in advance.
Ask to see the contractor's license and insurance policy. (Tennessee state law requires these.)
Be suspicious if you are asked to sign a blank contract, a completion certificate before the job is finished, or if the contractor doesn't allow you to contact him by phone.
Be suspicious if equipment and trucks are not marked with the company name and telephone number. (Tennessee law requires this.)