HAY! I made this test wich includes a brick wall with the blender logo as graffiti, and some rain. Tell me what to change, add or improve! xD
Hey.
Well, I couldn’t tell what the vertical lines were until I read they were supposed to be rain, so you can improve there. Make the drops alot smaller, alot shorter (not long lines), more transparent and add more of them there. You could also try lowering the saturation a bit or add light blue/grayish layer mix on the scene 
Thank you for your critique. As for the last one goes, i was going for a kind colorful big city night shot, so i preferably wouldn’t change that. I will post an updated picture soon! xD
good job, the second picture is really a great improvement. the lens flare really pops now. I would comment on the specularity of the bricks, but its raining.