Blocking In

I have just finished blocking in a new painting. I am working from a photo that I took one evening in the city of Lethbridge, Canada. Looking west beyond some buildings as the sun was setting, I saw the huge prairie sky studded with jelly bean shaped orange and apricot coloured clouds. In the foreground, dark buildings, parked cars, and trees were silhouetted against the colourful sky. Architectural features in the near foreground, such as wooden planters and a low retaining wall, created interesting shadows and reflected some of the orange glow. There also were patches of snow.

At this stage, I have blocked in the main areas of colour in the sky, as well as the dark buildings and foreground. Mostly, I have not started putting in the trees, except for a few dark marks placing some tree trunks relative to the other components of the scene. I will want to do more work on the sky first, and then paint the trees up into the sky. 

Although I am fairly happy with the shapes of the buildings, especially the one on the left hand side, I am really struggling to make the dark foreground dark enough. In my reference photo, everything but the sky is very dark, and even the bit of snow in the middle lower section is a mid-range value. 

This is a common problem for me. I tend to want to paint everything in high to mid values avoiding the dark tones, and in high key bright and light colours, avoiding shades of grey. But if the darks aren't dark enough, then the light and bright elements will not contrast enough to make them sparkle. So I have set myself the challenge of a night scene. I will keep working away at getting the darks darker. I am using raw umber, ultramarine blue, and paynes grey to make the dark values.