1. Vertical lines draw the eyes up. If you've got a focal point above, consider pointing your tiles in that direction. Here, they seem to flow right up into the matching sky.
In an even smaller application, Cor-Ten steel is found on a planter and framing a portal in the front of this townhouse. Here the rust is clearly used to complement the color of the door, both on the opposite spectrum of the blue steps and the variegated blue tiles of the facade.