Criticism of past employers
A sure way to put off a potential employer is to waste space on your resume criticizing past employers or supervisors. You may feel perfectly justified in your criticism, but the purpose of a resume is to showcase talents and abilities, not to air grievances.
Don’t give prospective employers the impression that you are disloyal or generally disgruntled. Instead, write about your positive relationships and accomplishments. Tell people about the good things you can bring to their business if they give you the opportunity.