Photoshop Sketch Composites
In this scene, the girls in the story are preparing to go outside to play in the yard. Their pregnant mom is cleaning the house and packing for a move. Queen Ferret, the central narrator and comic relief figure, is doing her best to cause trouble.
I started with these sketches (click on images to see larger versions):

I wanted the scene to be in a kitchen or hallway of a house, but I experimented with several backdrops before deciding on which to use.
To start, I found a photo of a kitchen that I liked, and an image of of a stack of moving boxes. I modified my sketch of the ferret pulling a sock out of a drawer into a drawing of her stealing something from an open box.

It was tricky finding a kitchen with the right perspective (from just under counter height, since the girls are sitting on the floor) but I eventually found one I liked and converted it into a grayscale sketch-type image using the Desaturate and Filter Gallery (Poster Edges) commands. I did the same thing to the stack of boxes and window image.
Next is the part I wish I had known when I did the glider painting, since perspective drawing has never been my strong suit. I took each of my sketches and cut out the backgrounds using the Magic Wand Tool, selecting the background and then inverting the selection to select the object only. I copied and pasted the images onto my kitchen image. Each pasted image went into a new layer. Next, I used the Free Transform command to scale, flip and rotate the pasted images into a composition that I liked. When I started, I wasn't sure if I would prefer to have the girls in the background or foreground, where to put the ferret, or how big each character should be in relation to the other. I shuffled the layers around to overlap the characters. Here's what I came up with as my painting mockup:

I extended the right edge and ceiling of the kitchen using the Clone Stamp tool on the background, and added a window showing the girls' backyard. I want to put a small detail into the backyard to tie into the story, but I haven't decided on one yet.
I think I liked this composition best because of the triangular layout that ties the characters together. The hillside in the window points down at the mother's face, her mop points towards the ferret, and the ferret faces the girls. The older sister's body angles back up at the mother.
As you can see, the goal is not to create an attractive drawing, but to experiment with composition in a quick and easy way prior to investing a lot if time. Had I been doing the composite sketch on paper, I would have had to erase and redraw each character every time I changed my mind. Now that I have my composite, I will transfer the basic lines to my canvas and paint it as a large full-color painting.

