I figured my Amell Warden was someone who was fairly practical when it came to his appearance, letting his black hair grow out and then tying it back into a short ponytail to keep it out of the way, which keeping his beard short and well trimmed. I also gave him blue eyes, since that eye colour seems to be a fairly common family trait judging by Leandra, Gamlen, Carver and FemHawke.
My Dwarf Commoners have green eyes and red hair tied back into either a ponytail or pigtails depending on their gender, making them look a lot like Rica. The Male Dwarf also has a short stubbly goatee, since most Casteless tend to not go for full beards. And I don't know why, but everytime I look at my female Dwarf Commoner, the immediate word that comes to mind is "bubbly".
Dwarf Nobles tend to have pale blond hair and blue eyes like Bhelen and Trian (and presumably Endrin before it turned white), with having the "Cailan" hairstyle with a short beard with few braids and the female having it in a short ponytail.
City Elf is another green-eyed redhead, to resemble both their cousins Soris and Shianni. Their hair tends to be short and rather messy, with or without simple facial tattoos depending on whether the mood strikes me?
Dalish Elves tend to have more regal black hair and green eyes, with the full face tattoo for a male and the upper half tattoo for women.
Human Nobles have dark brown hair (like their father, sibling and nephew) and green eyes (like their mother), with short hair for the men and longer hair for the women, while men share their father and sibling's goatee (it must be genetic). It made sense to me that there'd be an obvious resemblance since every single noble in the game immediately pegs you as "Bryce's son/daughter" when you meet them.