WIP, Having some concerns about the shadows on the girl, and lights on her face, their should be some reflected lights from the sunsets, but I'm having trouble figuring them out. Any crit would be helpful.
I've done a quick paint over to get my thoughts down. Hope you don't mind.
A lot of this lass is going to be in shadow due to the position of the sunset, leaving most of the sun to do edge lighting and contributing to some bounce light from the roof top she's leaping off. I saw the pink-ish light highlighting the right side of the pinnacle of the rooftop, so that could light the back side of her, giving some better sense of form. The red lights on the building in the background could be bright enough to get some highlights from.
The sun is low, so shadows will be elongated, and the city would probably be darker because of this.
Her anatomy seems to need a little fix. I feel we should be seeing more of her far side leg (probably the lower leg showing), and her arms seem a little awkward. Probably the arm closest to the viewer needs some adjustment.
I would incorporate more aerial perspective between the girl and the thing she is standing on and the buildingamajig with red windows. Right now it is very confusing. I thought the girl was flying because the two building masses seemed the same and it took quite while before I got what was going on. But I think the red windows are far enough and dim enough not to cast considerable backlight.
My first impression is that her arms look really long, particularly her right arm thats holding onto the building, and there's something wrong with the shape of her head. There also seems to be problems with the perspective and construction of the building itself.
I'm no expert but I think it might be better to work on the structures and forms first and worry about light and colour later.
The pose looks incredibly stiff. Her limbs and torso are very rigid, there's no twist to the torso, no bends in any of the limbs. Adding to that, her clothes are very starchy (aside from the scarf). No folds, no twisting fabric, no billowing in the wind.
Push the gesture. Create folds that facilitate eye flow.