Do The Research
You should never select the first company that you come across when selecting a contractor. The process of researching each company to find out what they are capable of, where they specialize and how much they will charge for the work is instrumental when it comes to making your decision, so make sure that you have all of that information for a number of different contractors before making a decision.
Licensed and Insured
You should never trust any contractor that is unable to provide the relevant licenses to prove that they are able to work in your state and on the project that you need them for. Furthermore, you need to pay special attention to the insurance that the company has so that you are covered in the event that something goes wrong.
Always Have A Contract
Anthony Tata points out that allowing a contractor to start work without having first negotiated and signed a contract that details the roles and responsibilities of every relevant party may leave you in a weak legal position should a dispute arise during the project. Make sure that this is secured before any work begins.