I will be honest, this can be difficult. I usually use my instincts, but i'm not always right. I find people perhaps those with families and children are usually pretty reliable.Once they dont start moving their 64 cousins.
You would want to make it very clear to them that any form of anti social behaviour or loud music will result in immediate eviction, and insert a sentence in the lease stating that fact.
Always ring previous landlord, and even employers if they are workibg. But beware that a landlord can be econimical with the truth if he is trying to get rid of problem Tennants.
Jack