Required: add doorways, windows, niches, columns or other architectural elements. Make sure to add depth to them!
You will be using a lot of Transform>Distort and >Perspective commands.
To add different values to your "walls" - use Levels (midtones)
Use Burn/Dodge tools for shadows and highlights on the objects.
Look for more images to use as "objects" to fill your space
Use Displace filters (spherize, displace, etc.), lighting effects, brightness control (use adjustment layer), Free transform, Warp, Liquify filter, Distort command and everything else you’ve learned so far in this class to create a surrealistic image where everything is made out of your pattern.
If you forgot how to use these filters - check the instructions for the previous projects