Perspective Challenge - Samples

We're going to be having a perspective challenge on Illustrated ATCs, and these are samples I'm using in the thread.

Here is my sketch to illustrate one-point perspective:

Here is a video in which Mark Crilley shows how you can make this using one-point perspective:

And here's another example of something he did with one-point perspective:

Here is my sketch of two-point perspective:

Here are two pieces made with two-point perspective by the inimitable SL Scheibe, aka Amerasu:

Here's a piece of Star Wars fan art that Mark Crilley created with two-point perspective: