From the initial brief, I thumbnail onto a printout- these initial sketches are about an inch or so square. I keep them small to capture the initial sense of the illustration. I don't want to get bogged down in details at this point.
I then go to digital for some composition layouts. The one in question here is the top one.
I wasn't totally happy with how this read so I thought I'd better go back to the drawing board. I did a quick biro sketch, about the size of a trading card. Here I focused on compositional elements. I want to achieve: 1) a line of action 2) adherence to the golden ratio and rule-of-thirds where possible, and 3) balance in the image. The viewer has to look at the right bits first, and move their eye around in the right order. We can use tangents, design elements and areas of contrast and/or detail to achieve this.
Next up I needed to clarify some details. Grabbing a little reference I worked up some of the elements. The main character, our psychically gifted lady, is based on a picture of Kristanna Loken: this was important as I had to feature her in another illustration and I wanted to ensure consistency in her facial features. While I didn't copy it exactly, I did use the topography of her face like a map.
Then I go to doing the linework. I do this all in Sketchbook Mobile on my phone. I did the character first and the background separately. I find it best practice to keep elements apart in case I need to change anything. Then I colour the flats. This is all black and white, so it's an exercise in tone work. Over the flats, I add a second layer, at a low transparency and then paint in solid black over this. I do this for all the shadows- doing it this way ensures consistency in the shadows, instead of darkening each separate element.
For the final piece I painted on some glow effects. These are done in an 'Add' Layer. Same as using a Hardlight Overlay in Photoshop. I painted all the spacefield in with different sized brushes- mostly dots with some hazy stuff. Like space. Then there is a greyscale picture of the sky overlaid on the whole image: this helps to unify the piece and adds a slight cell-shaded look. I keep lots of pictures of sky everywhere...
The final now reads a lot nicer than the original design. We can see the psychic images now lead us through the image. The eye goes to the character first, being the most detailed area, then we look at the images in order of size, flowing back through the character's face and away off to the horizon.
Hopefully it all works.