I'm not too confident in these paintings... But I did 4 designs. 3 landscape-ish paintings and 1 interior.
I was going for a toxic feeling world with this one. A bunch of sea creature alien slug things are sailing into this alien harbor. There's an indication of a sinister looking city in the distance and there are some foreground insect like arms that might be loading cranes for the alien slug boats:
A mysterious cliff side town shrouded in mist and fog with a foreground element of a caravan heading towards the town:
Here's a black and white interior painting based on the starting few chapters of the novel Perdido Street Station by China Mieville: