Honestly, most of the time the ghost is confused or is hanging around because it doesn't realize it's dead. If you simply speak to the entity and tell it that this is no longer it's place, it's necessary for it to move on and be at peace, that's usually the best.
Obviously if you get a violent spirit, or a demon, or something that doesn't want to move on, then you'll need to bring in some heavy hitters, but other than that it should just be as simple as possible.