It started with a horizontal & a vertical flip, and a blend. Drag the top layer around to find something interesting.
Crop to a square.
Not much there but clouds & towers, flip'n'blend to get some action going.
Flatten.
Copy to a new layer. Warp'n'Blend. Copy that layer to a new layer, flip horizontal and vertical to get a diagonal mirror & blend again.
Add a layer of SEP2 Film Noir 3 at 90%.
Heave a sigh of appreciation.
Flatten. Save for web.