I always think this stage is fascinating psychologically. Whenever I get a chance to see how other artists think, I can learn something from it so hopefully there is something here for those people who have asked to see how I develop some of my ideas. You can see how this rough evolved into the final comp, below, which I will use as a rough guide to do an oil painting from. Since these roughs are really spontaneous and without much conscious thought, just scribbles really, the resulting image can be a curious insight. 

Note the boat on the left side, or the cloth I originally wanted behind the column.  Why? I think with most realists it's part what they enjoy painting, part composition and elements to help make the work look better, and, of course, the meaning behind each piece. For me, at least on this image, I wanted to have fun and do a cool fantasy piece, part of a series, and part of the idea is adding elements to make the work come to life a bit more. Moving on to the next stage always results in a bit of a compromise, but that's the exciting part of not knowing exactly what you are after or going to get in the final. Fantasy work is like that- never knowing just what to expect until you are finally done- whereas traditional realistic work, like so much gallery painting, emphasizes technique over creativity and the idea of painting what you see, not what is in your head. Both have their place. For myself, I try to do some of each, balancing both needs to follow nature, and to invent.

After shooting a couple of models for the right pose, I put together a quick sketch then refined it into this line drawing, done at high enough resoulution, 300ppi at around 10x15, so that I could get into the tighter areas and add clean lines without worry of a jagged or diffused edge. Another way to do this, of course, is traditionally, using pencil or ink and straight edges, etc, to do a final drawing I can scan in easily. I prefer to use the advantages of the computer to draw in the background and draw out the figures, which I can clean up now by simply sketching out the initial rough, adding a white layer that is around 50%, like tracing paper, then drawing over that with a cleaner line. Digitally, I can get very clean linear effects (straight and angled lines, curves, elipses, etc.) so its a beautiful medium to create professional linear work and a great start for this particular technique.

From this line art, if done with closed areas, it's quite easy to create channels (masks) that I can keep to do the airbrushing with and fill in the areas with local color, below. 

Above, the half-tones are filled in by airbrushing and tablet painting until the figures and background looks fairly solid. I don't need to overdo this. I just want to see what it looks like to help me visualize a full comp, in case I want to paint it with traditional medium (oil).

Below, the final comp has the kind of look I like, just enough to let me know whether I should pursue this piece as a final oil painting. Of course, just painting it in oil is a whole new approach and will look somewhat different, but it's helpful to have this comp to use as a color study, if nothing else.