i did most of them from my head (The stylized one) with some reference from my teacher's examples, and some references from anime/manga/books for poses, etc.advice for envrionments: don't start out wit hthe perspective grid. especially when doing these sketches. concentrate on finding the shapes. interesting shapes. foreground, midground, background. have about 3 main shapes as focus, and the rest should be less detailed. find shorthands for repeating things (i.e. rectangles for columns, etc).
ok cool dude. thanks for the advice.