I understand what you're trying to show with transparency layers and blue lighting, but the problem is that I haven't used Photoshop for other than some pixel art, an example being this background. I've also tried to accomplish this with ArtGem, but the interface just infuriated me to click the "Close" button before I can actually get accustomed to it (I'm a patient guy in real life, but technology can be a pain when it doesn't work as it should). At the same time, I hate to say it, but I found your descriptions, although clear as to what I should be doing, are simply far too vague for me in terms of the steps needed to accomplish this work
So for instance, when you say "to remove bits of red and green" are you referring to channels? Because the problem is in Photoshop, removing the channels leaves me with a black-and-white picture. If it's putting a color layer on top and removing opacity, then it's just like a blue haze looming over the background. Same goes for transparent areas, as your link talks about applying a layer over the original picture, which is fine for me, but the way you made the blotches of gray and white just throw me off.
Sorry if it sounds like I'm asking dumb questions, but like I said, I don't have photo experience, just simplistic pixel art.

EDIT: After some more tinkering around, I find can sort of get the bluish lighting if I use a layer mask set to vivid/dark light, then a couple of layers set to about 15-20% opacity, as you described, so fortunately I get that part figured out. I'm still just a little curious as to how to managed to do random shading without making it look like an image that someone has sat on for a few hours. Same goes for your transparency mask. I think I was too frustrated to have any real progress at the time of writing my previous post, but I'd still like to know more as to how you accomplished the final product.

So, I've tried my best at getting a few of the things fixed, and this is what I turned up with after an hour or so actually trying to figure out some of the finer details:


The night atmosphere works, but the shading of the building and the ground, at least in my opinion, looks like a random mess which might have been a decent picture, but was sat on for a long period of time. Mainly, my question here is, what do you do when it comes to shading to make it look so professional and organized?

(Combined posts) - ProgZ