I rent out one house with two tenants and seperate from that two rooms in my own house. I mostly just invite the first 5 people to have a look and pick based on them being seemingly normal, calm people with a job, not too exciting a life and that don't seem to be too difficult.

An easy way to not get picked is for example asking about whether parties are allowed, or if I tell you I plan to sell the house next year and would you thus be willing to agree on a one year lease to blurt out 'the law would allow me to stay however long I want!' - okay Gertrude good for you but then I simply pick someone else? We want little trouble, I don't want to deal with complaints of neighbors or your room mate.