Using Black Paper

Don't worry. It's not going to be a gaudy "Velvet Elvis", but working on black paper has the benefit of making your pastel colors very vibrant. I like Uart Dark 400 grit and it's very dark but not actually black.
Here's the reference photograph. 
When creating the painting I emphasized the shadows so that the painting would be about 66% shadow and 34% sunshine. It's always better to not have the painting evenly divided between light and shadow. By making more of the image in shadow the sunny areas will become the focal point.

Reference photograph for "Artist and Teacher" Notice I've drawn 1/3 grid onto the photograph

This paper is very dark, so the first layers will be dark, but don't despair. The next layers of color will brighten up the scene. I drew the basic shapes with an orange Conte pastel pencil.

Sketch in the basic shapes. Watch the composition so that the point of interest (artist and teacher) are not in the center.

In step 2 I blocked in the shadow areas and the sunny areas. And in step 3 I blocked in the light sky, the tree shapes and emphasized the sunny area.

Here's an ink sketch of the main subjects - Artists and Teacher. The photograph was taken at a Plein Air workshop with Kim Casebeer who is discussing the scene with one of the participating artists. I liked the way they were sitting in the shadow area with the sunlit area behind them. 

In step 4 I start lightening up the darker areas and using colors closer to the reality of the scene.

The final step shows more layers to get the value correct between light and shadow areas.
 I lightened the background and the large tree to the left of the figures so that area will drop back and add to the feeling of depth and atmosphere. I also lightened the shadow part of the grass so that the darks of the tree shadow would be darker than the grass. You'll see the color swatches along the left side of the pastel. I'm using this image for my Tuesday night pastel class and they will be able to see which pastels I used in the piece.

Color Bias - "Tay's Road"

Artists can chose to copy the color they seen in the landscape OR you can interpret and adjust the color to create a mood or emphasize a time of day.
In this lesson I take the same photograph and create one image with warm, light, early-morning colors and in the second image I change the colors to be more blues and greens emphasizing the late afternoon light. I call this color bias.
Here's the reference photograph.

"Tay's Road" late afternoon. This is a good example of selective images. I'm eliminating the dog and the artist and the car hidden behind the orange branches on the left and the overhanging branches on the right.

Starting the image with a line drawing of the important shapes. I'm working on Uart 400 sanded paper with a thin acrylic wash to color the paper.

Line drawing of the important shapes

Starting the "Morning Light - Tay's Road" I blocked in the major shapes using a dark blue in the shadow areas and orange for the sunshine areas. When using pastel you want to start with darker colors and use lighter colors as you add layers.

Start blocking in the basic shapes. Keep in mind your purpose for the image - morning light.

Now start adjusting the layers by using colors that are in medium tones. In the "Morning Light" image I even want to use warm color in the shadow areas to emphasis that warm summer morning light.

Blocking in warm tans in the shadow of the road, greens in the shadow of the woods on the right that you can't see and yellows in the middle ground area with the 2 small barns on the left of the road.

The final layers are an adjustment from the reference photo to emphasize light. Most of the colors I used are either mid-value or light values. If you took a b/w photo of the final piece (which I suggest as a great way to evaluate your values) most of the grays should be on the lighter side of mid-tones with maybe 30% of the image in shadow.

Final image. The little colors on the left side are the pastel colors I used in the demo.

This is a long lesson but I want you to see the next pastel so you can compare how I adjusted the colors. "Afternoon Light - Tay's Road" is the final version which I want you to see at the same time as "Morning Light - Tay's Road" so you can compare my color choices.

This is the final version of "Afternoon Light" Notice the emphasis on cool shadows and I added more shadows in the foreground so the viewer will get the feeling of walking from a cool shadow area in the light in the background.

Here are the steps in creating "Afternoon Light".

Step 2 of "Afternoon Light"

Step 3 of "Afternoon Light"