When choosing the perfect roommate, whether you are the tenant or the landlord, a little common sense and due diligence should be a pre-requisite before making your decision.
Several factors come into play for both the landlord and the tenant.
As a landlord, you are bringing a relative stranger into your household who could prove to be the perfect way to offset your costs, or turn into an additional expense for you to bear. First of all, you will want to judge the prospective tenant's fiscal responsibility. To do this you will need to have a signed authorization from this individual and contact any number of consumer reporting agencies. To supplement the consumer report the data you will obtain from the report, it is a good idea to also contact your prospective tenant's previous landlords for references and rental history. They will give you a good idea as to exactly what kind of person this is and what behavior that you might expect from them.