mechanized:

Hello and thank you! C:

I’m just going to throw some links to tutorials here at you because it’s easier than explaining on my own, haha.

Unique Features pt 1 (body types)
Unique Features pt 2 (female faces) 
Unique Features pt 3 (male faces) 

Female Body Tutorial (note that the same can be applied to male characters with a few modifications - e.g. the bust/waist/hips/thighs can be modified to shoulders/chest (ribcage)/thighs for male characters, and can be expanded to include neck, shoulders, arms (both upper and lower), and calves for both sexes - all can have varying sizes in any given character, which is what creates a unique silhouette)

Guide to Human Types pt 1 (Asian)
Guide to Human Types pt 2 (Caucasian)
Guide to Human Types pt 3 (African and Pacific Islands)
Guide to Human Types addendum

Skin: A Chart (note that this is a supplement to a tutorial on how to paint skin, linked in the description to the image)

Younger vs. Older features (a non-realism view on how to make characters look younger by reducing facial detail - not applicable to all styles and character designs but it can be a helpful thing to keep in mind)
Guide to Aging Characters

Ethnic Hair Types pt 1

…I get the feeling I’m forgetting to link something (and for the life of me I couldn’t find anything good on how to draw fatter characters), but there’s the basics I can remember.