A portrait can be of a person, place or thing, but to me, people are usually more interesting. A portrait of a person can be posed or candid, but I feel a formal sitting is more interesting. Then it really has to be a two way street. I have a modest ability in setting up a camera, adjusting light, loading film, and so forth, but once this is done, the burden of responsibility shifts. If the person being photographed gives nothing back the process is a waste of time. If the photographer has the ability to coax a subject into giving a little, it makes things a little easier. These are examples where the subject gave something back.