I'm thinking about a loose, more contemporary style, with lots of bold color to create a sense of action, speed and grace. As I'm looking to be original and different in composition I didn't want to depict more sliding reining horse side views that is very common. So I went with a left hand spin horse, a right hand spin horse and in the center a front view sliding stop. Here is a working sketch drawn freehand from references:

And I've started on the background using wet pencils and washes on dry paper, size is about 6" x 10" :

Next I'll "tighten" up the sketches, refine the lines and get them where I want to transfer onto the painted background. Then the color will begin!! Stay tuned....