So far, probably less than they should. For example Sylvie does stand out in most crowds...
When making up looks for someone, I mainly go by "what do my other characters, particularly ones that interact with this one, not look like?", except when I want a certain (family) resemblance in there. And I realise there are vast categories I haven't even started tapping yet.
Sometimes there's "what kind of look goes well with their personality?"
Sometimes there's "I like this and that character from comic/movie/whatever X, let's start mine looks-wise as a variation of them".
And, well, I try to pay some attention to what real people look like, and mix and match a bit, particularly using somewhat unusual features, to keep the characters recognisable. (Sylvie got her eyebrows from a woman I saw on the bus once. Gabriel got his current nose based on my maternal grandfather's, when I noticed he was too similar to another character of mine. Stuff like that.)
