Clothing: I try to stick to a general theme. I add more detail than I would using simplification, but I still try to remember that players often do not remember everything. The clothing will often reflect some of the personality of the wearer.
Face and body: I actually try to evade stereotypes when creating major npcs. Cliches might be useful for their ease of use and remembrance, but no important character should come off the assembly line.
What I do is that I study everyday people. Sooner or later someone interesting is bound to appear, someone fitting for the role. Then I use their appearance. Often I have already met the candidates.
I always repeat how the character looks, because otherwise the players will forget and just remember a name (if I am lucky). The trick is to repeat it in an interesting way. No player will want to listen to the same description twice, so I weave his looks and personality into the telling.
Example: \“The thin, young man leans back against the wall. He regards you with a mischievous gleam to his brown eyes. He waits just a second longer than is appropriate, before he replies in his usual reedy voice ...\”
Personality: Personalities are important. Important characters often have strong personalities. I always try to imagine what upbringing and training the individual has. A royal princess will most likely be spoiled, with little or no empathy for others. If she has had a stepmother or an abusive and foul tempered father, she might be more humble.
As with everything I try to picture people I have met. If I want to describe a cleric, I think of the priests I have met and then adjust them to their particular religion. I always think of real people and spice them up with my own imagination.
Desired outwards appearance: This is important and takes precedence over the real personality. There are several ways the desired outwards appearance could be discovered to be untrue, like through the area of effect.
The desired outwards appearance will be what the NPC wants to appear as. There has to be a motive for his deception. A spy has a very natural reason to be deceiving and might be very talented, while a \“charming wife\” might want to be the sole beneficiary of a PC.
Area of Effect: With major NPCs this is very important. The powerful will have a large, huge even, area of effect. This will often hint at their true personality and might be the only clue the PCs will get if they are being deceived.
Some simple examples:
An assassins area of effect will be mysteriously dead friends and acquaintances. It will be rumours among the populace and it will be the fear in the vicinity of his activities.
A blackmailing noble\‘s area of effect will be hateful, nervous other nobles and persons of importance. It might also show through the obvious economical decline of some merchant and in the prosperous economy of the blackmailer. Blackmailing might be anonymous or it might not. It might end in murder, divorce, bankruptcy or something else.
Most people you meet won\‘t lay their entire life\‘s story at your feet. You will get a first impression (possibly the desired outwards appearance) and with time you might get to know the real person within.
I use this in my game mastering. I serve little bits to my players who will then get a first impression. Then I gradually serve them this and that, while at all times contradicting this new evidence with the desired outwards appearance. If there is no desired outwards appearance to speak of, the players will soon enough discover the real person.
Voice Acting: Voice acting is more important than ever. It shows much of the personality of the NPC, possibly more than they wish to convey. The \“charming wife\” might explode in sudden, hateful, bursts of anger (with out of character gutter snipe swearing mixed in) and then suddenly become honey sweet again.
A duke, accustomed to command, will have a strong, imperious tone of voice. If he is a fake he might easily stumble where a real duke would not.