After some very quick ideation sketching I did this rough. My main considerations here were character and communicating the concept. I already had an idea for lighting but instead of indicating it in this sketch I focused on just concept and communication.
After feeling confident about the design I moved into detail and refining and designing. Here I made little visual notes to remind me of what I want to do later on in the rendering. I want to "keep something in the tank" and leave some exciting bits to be explored, I don't want to figure it all out yet. I find this keeps me interested and leaves room for happy accidents and surprises. I make sure to save a flattened copy of this on a multiply layer to refer to once I start painting.
My next step was to drop in a color ground and begin blocking in large forms. I begin painting under my drawing to maintain the integrity of the design, I also let the ground show through in places for variety. I paint on top of the drawing when I want to make the form more 3-D. I find this helps maintain the original character of the drawing.
The swatches are there to help me maintain the color relationships I want.
I am only concerned with the lighting coming from above at this point. It is easier to concentrate on one light source at a time.
You may have noticed that I flipped the canvas. I do this to get "fresh eyes" on the painting. At this stage I lay down a rough blocking of the lighting.
This a close up of the refined cyan light source.
I have been reading about Howard Pyle and how he used to edit his paintings down to what was only necessary. At this point I asked myself "what is the cane doing for me? Does it help tell the story? Is it distracting?" I decided it wasn't doing a whole lot so I added a smashed jack o' lantern. I dropped in a white layer on %60 opacity and drew on another layer on top. I want to see enough of the composition to make the pumpkin work but not so much as it distracts from my drawing the new element.
This is an example of me checking the drawing against the painting using the same method I described above.
The finish! I hope this was helpful, if anyone would like to know about anything I haven't covered here just ask.