My mother always said “don’t generalise”, but when it comes to role-playing, go big or go home. And if you’re at home, just go bigger. Big generalisations give us a point of reference that’s such a key to entertaining sessions. Heavy Scottish accents indicate dwarves, that’s pretty much a tradition of the hobby. Evil villains sound evil: they cackle as they deliver their diabolical monologue.
Don’t do what I did. I’d heard advice like this before, but in my mind “subtle” was always a better option. Boy was I wrong. Subtle characters are effectively watered down and they become bland, tasteless and unrecognisable amongst the scores of other watery NPC’s. When you make generalisations that support players assumption, you confirm aspects of the world that are a cornerstone of their understanding. Yes, the dwarf could have any accent, or none at all, but a Scottish accent is expected. The merchant who speaks with an Indian or Egyptian accent might well be looking for a good deal, even if he’s from Calimshan rather than Calcutta.
It’s all about character, so ham it up. Use those cues to make your characters truly unforgettable.