Contractors essentially need to be entirely piecework - I am paying you to accomplish this task, by this date, end of story. If the employer attempts to impose

Contractors essentially need to be entirely piecework - I am paying you to accomplish this task, by this date, end of story. If the employer attempts to impose conditions on how the work is done, or when it is done (in terms of working hours, etc) then those are characteristics which point towards the contractor actually being an employee of the company.