Make sure you screen tenants carefully through your reference checks and absolutely do not give someone the benefit of the doubt. If they have bad credit history, you should insist on a guarantor or better still look for another tenant. Where I can, I try to stick to tenants with a strong employment history. By this, I mean that I look for both long service with a single employer and some level of professional qualifications in an industry that is going to be in demand for some time.