Verify that the contractor has the proper license and insurance for his/her profession.*
Ask for and check the contractor’s references.*
Not hire any contractor that has an out of state address.
Have a written contract between you and the contractor listing the specifics of the job and any materials being used. The state of Massachusetts requires any job over $1000 (One Thousand Dollars) to be in writing. This does not bar you from requesting the details of a job to be in writing for any amount, even less than $1000.
Not to agree to any additional work without a written agreement between you and the contractor specifying the details of the added job.
Have a pay schedule between you and the contractor. This should be specified in the contract with regards to deposit, frequency and amount of payments, and any finance charge.
* BrooklineCAN volunteers have completed these steps for contractors listed here. This work was last done in 2014, so it may be out of date now.