
TRSE: How To Draw Tutorials:
Some Pointers on Advanced 3D Concept
Here's few more examples:

You may have noticed that the lines coming from one
point can be used to help guide the drawing of a man from "a child's point
of view"(looking up at the man from below). Another lines from another
point can be added to produce a different character to the right. Notice
that the character on the right seem smaller than the first character and
that is because the first character is much closer to the foreground.