An oldie but goodie...
A while ago, I picked up a book called Subway Sketches which is filled with...yeah you guessed it, sketches of people that a bunch of artists drew while riding the subway.
Anyway, since then I've been finding myself opening the book a lot and always finding inspiration to draw. In one part of the book, it shows simple steps of drawing the profile of a person:
So here's a page I did of a bunch of random people I made up.