For my main NPCs I've created a couple of photo portraits using Photoshop.
The first NPC is Joseph Williamson Esq. As land agent for the Earl of Cadogan, the owner of Carlton House (and in fact the whole of St George's Square) he is acting on behalf of his employer in seeking help to solve the mystery of the property.
As you'd expect of such a prominent figure in the Earl's retinue, he is a confident, businesslike and well turned out man about town, reluctant to get his hands too dirty with the whole affair:
My second portrait is of Edmund Gower, Professor of Moral Philosophy at the University of London and President of the Society for Psychical Research. His character is that of the stereotypical absent-minded but enthusiastic academic. A single man, he has a modest but well-kempt residence in Bedford Place, Bloomsbury, near to the University. This is also where the Society for Psychical Research meets once a month. It is Professor Gower who presents the Players with the task of investigating Carlton House, and acts as intermediary in all dealings with Joseph Williamson: